CDS (II) 2024 — Elementary Mathematics (Full Question Paper)

A real number x is such that the sum of the number and four times its square is the least. What is that number?

• (a)-0.625
• (b)-0.125
• (c)0.125
• (d)1

The difference of the square of two natural numbers m and n (m > n) is 72. How many pairs of natural numbers will satisfy?

• (a)3
• (b)4
• (c)5
• (d)6

Let N be a 5-digit number. When N is divided by 6, 12, 15, 24 it leaves respectively 2, 8, 11, 20 as remainders. What is the greatest value of N?

• (a)99960
• (b)99956
• (c)99950
• (d)99946

What is the remainder when 111²²² + 222³³³ + 333⁴⁴⁴ is divided by 5?

• (a)1
• (b)2
• (c)3
• (d)4

What are the last three digits in the multiplication of 4321012345 × 98766789?

• (a)1, 0, 5
• (b)2, 0, 5
• (c)2, 1, 5
• (d)3, 0, 5

p varies directly as (x² + y² + z²). When x = 1, y = 2, z = 3, then p = 70. What is the value of p when x = -1, y = 1, z = 5?

• (a)100
• (b)125
• (c)135
• (d)140

Let N be the least positive multiple of 11 that leaves a remainder of 5 when divided by 6, 12, 15, 18. Which one of the following is correct?

• (a)900 < N < 1000
• (b)1000 < N < 1100
• (c)1100 < N < 1200
• (d)1200 < N < 1300

What is 1/(√10+√9) + 1/(√11+√10) + 1/(√12+√11) + … + 1/(√196+√195) equal to?

• (a)17
• (b)14
• (c)11
• (d)10

Train X crosses a man standing on the platform in 24 seconds and train Y crosses a man standing on the platform in 18 seconds. They cross each other while running in opposite directions in 20 seconds. What is the ratio of speed of X to speed of Y?

• (a)1:2
• (b)2:3
• (c)1:3
• (d)3:4

Let p, q be the roots of the equation x² + mx – n = 0 and m, n be the roots of the equation x² + px – q = 0 (m, n, p, q are non-zero numbers). Which of the following statements is/are correct?
I. m(m+n) = -1
II. p+q = 1
Select the answer using the code given below.

• (a)I only
• (b)II only
• (c)Both I and II
• (d)Neither I nor II

What is the maximum value of 8sinθ – 4sin²θ?

• (a)3
• (b)4
• (c)8
• (d)12

What is (1 + tanα tanβ)² + (tanα – tanβ)² equal to?

• (a)tan²α tan²β
• (b)sec²α sec²β
• (c)tan²α cot²β
• (d)sec²α tan²β

Consider the following statements:
I. tan50° – cot50° is positive
II. cot25° – tan25° is negative
Which of the statements is/are correct?

• (a)I only
• (b)II only
• (c)Both I and II
• (d)Neither I nor II

If 0 ≤ (α-β) ≤ (α+β) ≤ π/2, tan(α+β) = √3 and tan(α-β) = 1/√3, then what is tanα·cot2β equal to?

• (a)1
• (b)√2
• (c)√3
• (d)1/√3

What is the value of sin²θ cos²θ (sec²θ + cosec²θ) equal to?

• (a)0
• (b)1
• (c)2
• (d)4

If 64^sin²θ + 64^cos²θ = 16 where 0 ≤ θ ≤ π/2, then what is the value of tanθ + cotθ?

• (a)1
• (b)2
• (c)3
• (d)4

If cosecθ – cotθ = m and secθ – tanθ = n, then what is cosecθ + secθ equal to?

• (a)(1/2)(m + n + 1/m + 1/n)
• (b)(m + n + 1/m + 1/n)
• (c)(1/2)(m + n – 1/m – 1/n)
• (d)(m + n – 1/m – 1/n)

From a point X on a bridge across a river, the angles of depression of two points P and Q on the banks on opposite side of the river are α and β respectively. If the point X is at a height h above the surface of the river, what is the width of the river if α and β are complementary?

• (a)2h(tanα + cotα)
• (b)h tanα·tanβ
• (c)h cotα·cotβ
• (d)h secα·cosecα

In a triangle ABC, ∠ABC = 60° and AD is the altitude. If AB = 6 cm and BC = 8 cm, then what is the area of the triangle?

• (a)12 square cm
• (b)12√3 square cm
• (c)24 square cm
• (d)24√3 square cm

If p and q are the roots of the equation x² – sin²θ x – cos²θ = 0, then what is the minimum value of p² + q²?

• (a)1/2
• (b)1
• (c)3/2
• (d)2

The arithmetic mean of n numbers is M. If the sum of first (n-1) terms is k, then what is the nth number?

• (a)M – k
• (b)nM – k
• (c)n(M – k)
• (d)M – nk

What is the geometric mean of 3, 9, 27, 81, 243, 729, 2187?

• (a)81
• (b)105
• (c)144
• (d)243

A person purchases one kg of tea powder from each of the four places A, B, C, D at the rate of ₹1000 per 1 kg, 2 kg, 4 kg, 5 kg. If on an average he purchased x kg of tea powder per ₹1000, then what is the approximate value of x?

• (a)1.95
• (b)2.00
• (c)2.05
• (d)2.10

What is the sum of the largest and the smallest 4-digit numbers made by using single digit prime numbers (without repetition)?

• (a)7887
• (b)7997
• (c)8998
• (d)9889

What is the remainder when 3²⁵⁵ is divided by 28?

• (a)1
• (b)11
• (c)24
• (d)27

What is the value of x (0 ≤ x ≤ 8) if (100⁹⁷ + 100⁵⁴ + x + 1) leaves a remainder 0 when divided by 9?

• (a)8
• (b)6
• (c)4
• (d)1

In a triangle ABC, D is a point on BC. If AB·DC = AC·BD, ∠BAD = α and ∠CAD = β then which one of the following is correct?

• (a)α = β
• (b)α = 2β
• (c)2α = β
• (d)2α = 3β

Let N = 12345678AB be a 10-digit number, where A, B are digits. If N is divisible by 9, then which of the following statements is/are correct?
I. (A+B) is divisible by 9
II. If A is odd, then B is odd
Select the answer using the code given below.

• (a)I only
• (b)II only
• (c)Both I and II
• (d)Neither I nor II

If x³ + 1/x³ = 65/8 and y³ + 1/y³ = 730/27, then which one of the following is a value of xy?

• (a)3
• (b)6
• (c)8
• (d)9

If 11x + 5y is a prime number where x, y are natural numbers then what is the minimum value of (x+y)?

• (a)3
• (b)4
• (c)5
• (d)6

A 4-digit number N has exactly 15 distinct divisors. What is the total number of distinct divisors of N²?

• (a)16
• (b)30
• (c)45
• (d)225

If p, q and r are the lengths (in cm) of the sides of a right-angled triangle, then (p-q-r)(q-r-p)(r-p-q) is always

• (a)Positive only
• (b)Negative only
• (c)Non-positive only
• (d)Non-negative only

What is the minimum value of (a⁸+a⁴+1)(b⁸+b⁴+1)/(a⁴b⁴), where a > 0, b > 0?

• (a)1
• (b)4
• (c)9
• (d)16

In a class containing 200 students, n students prefer both tea and coffee; 2n students prefer coffee, 3n students prefer tea; 4n students prefer neither tea nor coffee. What is the value of n?

• (a)20
• (b)25
• (c)30
• (d)35

Let ABC be a triangle with area 36 square cm. If AB = 9 cm, BC = 12 cm and ∠ABC = θ, then what is cosθ equal to?

• (a)√5/3
• (b)√5/4
• (c)1/3
• (d)2/3

Let n be a natural number. The HCF of n, n+10 is 10. If the LCM is x (a 2-digit number), then how many values of x are possible?

• (a)Only one
• (b)Only two
• (c)Only three
• (d)More than three

What is HCF of a⁴+2a³+3a²+2a+1 and a⁶-2a³+1?

• (a)a³+3a²+2a+1
• (b)a³+a²+a+1
• (c)(a²+a+1)²
• (d)(a²-a+1)²

If the roots of the equation x² – (k-2)x + (k+1) = 0 are equal, then what are the values of k?

• (a)0, 4
• (b)0, 8
• (c)4, 4
• (d)2, 6

What is [(cosθ-sinθ+1)/(cosθ+sinθ-1)] (cotθ-cosecθ) equal to?

• (a)-1
• (b)0
• (c)1
• (d)2

What is (sinθ – 2sin³θ)/(2cos³θ – cosθ) equal to?

• (a)sin²θ
• (b)cos²θ
• (c)cotθ
• (d)tanθ

The mean weight of 150 students in a class is 60 kg. The mean weight of boys in the class is 70 kg and that of girls is 55 kg. What is the ratio of number of boys to number of girls?

• (a)1:2
• (b)1:1
• (c)2:1
• (d)2:3

Two towers A and B of height 23 m and 11 m respectively, stand 9 m apart. A straight rod is joined to the two tops of the towers. A monkey sitting on the top of A, climbs the rod to reach the top of B. If the monkey takes 5 minutes to reach the other end, what is the average speed of the monkey?

• (a)10 m/min
• (b)5 m/min
• (c)10 cm/sec
• (d)5 cm/sec

A spherical wooden ball of radius r is to be divided into eight identical parts by cutting by planes passing through the same diameter. What is the surface area of each final piece?

• (a)πr²/3
• (b)3πr²/2
• (c)2πr²/3
• (d)4πr²/3

A trolley with two wheels one metre apart is moved clockwise on the circular track around a ground with radius 50 m (described by right wheel). If the size of each wheel is of 1 foot radius and the right wheel turns 1000 times, how many times will the other wheel turn?

• (a)1010
• (b)1015
• (c)1020
• (d)1025

What is the remainder when 70 × 71 × 72 × 73 × 74 × 75 × 76 × 77 × 78 × 79 is divided by 1000?

• (a)3
• (b)2
• (c)1
• (d)0

A vertical pole of length 80 m is situated on the horizontal plane. The base of the pole is at P. There are two points A and B such that P, A, B are on the same straight line. Let the angles of elevation of top of the pole from A and B be α and β (α>β) respectively. If PA = 64 m and AB = 36 m, then what is (α+β) equal to?

• (a)60°
• (b)90°
• (c)120°
• (d)135°

Let k be a positive integer. What is the quotient when x^8k+3 + x^8k+6 + x^8k+9 + x^8k+12 is divided by (1+x³)(1+x⁶)?

• (a)x^8k
• (b)x^8k+1
• (c)x^8k+2
• (d)x^8k+3

A square is drawn inside a square of side 14 cm in such a way that the corners of the inner square coincide with the mid points of the sides of the outer square. What is the area lying between the two squares?

• (a)98 square cm
• (b)56 square cm
• (c)49 square cm
• (d)24.5 square cm

The base of a right-angled triangle is 4/3 times the height of triangle. If the area of the triangle is 54 square cm, then what is the perimeter of the triangle?

• (a)30 cm
• (b)32 cm
• (c)36 cm
• (d)40 cm

What is the area of a triangle having sides 4, 4 and 6 units?

• (a)3√7 square unit
• (b)8 square unit
• (c)7 square unit
• (d)7√3 square unit

What is tanθ equal to?

• (a)1/2
• (b)1/3
• (c)1/4
• (d)1/5

If ∠ACP = γ, then what is tanγ equal to?

• (a)1/2
• (b)1/3
• (c)2/3
• (d)1

Consider the following statements:
I. The line segment AP divides the area of the triangle ABC into two equal parts
II. The perimeter of the triangle APC is more than 46 cm
III. The area of the triangle APC is 50 square cm
Which of the statements given above are correct?

• (a)I and II only
• (b)II and III only
• (c)I and III only
• (d)I, II and III

What is the median of the distribution?

• (a)44.9
• (b)45.5
• (c)45.9
• (d)46.3

What is the mode of the distribution?

• (a)47.25
• (b)47.75
• (c)48.25
• (d)48.75

If ∠BAC = θ then what is sinθ + cosθ equal to?

• (a)1
• (b)71/65
• (c)73/65
• (d)79/65

If BD is the perpendicular on the side AC, then what is the length of BD?

• (a)1008/65 cm
• (b)756/65 cm
• (c)168/7 cm
• (d)165/7 cm

What is OQ equal to?

• (a)5 cm
• (b)6 cm
• (c)7 cm
• (d)8 cm

What is PM equal to?

• (a)10 cm
• (b)12 cm
• (c)40/3 cm
• (d)50/3 cm

What is the area of triangle OMN?

• (a)36 square cm
• (b)40 square cm
• (c)45 square cm
• (d)48 square cm

A question is given followed by two statements I and II. Consider the Question and the Statements and mark the correct option.

Question: What is the integral value of k for which the expression 4x² – kx + 1 is positive?

• I.k < -2
• II.k > -4

Which one of the following is correct in respect of the above Question and the Statements?

• (a)The Question can be answered by using one of the Statements alone, but cannot be answered using the other Statement alone
• (b)The Question can be answered by using either Statement alone
• (c)The Question can be answered by using both the Statements together, but cannot be answered using either Statement alone
• (d)The Question cannot be answered even by using both the Statements together

A question is given followed by two statements I and II. Consider the Question and the Statements and mark the correct option.

Question: In how many days can A, B and C together finish the work?

• I.A and B together can finish the work in 24 days
• II.B and C together can finish the work in 36 days

Which one of the following is correct in respect of the above Question and the Statements?

• (a)The Question can be answered by using one of the Statements alone, but cannot be answered using the other Statement alone
• (b)The Question can be answered by using either Statement alone
• (c)The Question can be answered by using both the Statements together, but cannot be answered using either Statement alone
• (d)The Question cannot be answered even by using both the Statements together

A question is given followed by two statements I and II. Consider the Question and the Statements and mark the correct option.

Question: Can we have a common solution which is prime?

• I.x² – 26x + 133 = 0
• II.x² – 44x + 475 = 0

Which one of the following is correct in respect of the above Question and the Statements?

• (a)The Question can be answered by using one of the Statements alone, but cannot be answered using the other Statement alone
• (b)The Question can be answered by using either Statement alone
• (c)The Question can be answered by using both the Statements together, but cannot be answered using either Statement alone
• (d)The Question cannot be answered even by using both the Statements together

A question is given followed by two statements I and II. Consider the Question and the Statements and mark the correct option.

Question: Is 327ⁿ + 173ⁿ divisible by 500?

• I.n is odd natural number
• II.n is a positive integer

Which one of the following is correct in respect of the above Question and the Statements?

• (a)The Question can be answered by using one of the Statements alone, but cannot be answered using the other Statement alone
• (b)The Question can be answered by using either Statement alone
• (c)The Question can be answered by using both the Statements together, but cannot be answered using either Statement alone
• (d)The Question can be answered even without using any of the Statements

A question is given followed by two statements I and II. Consider the Question and the Statements and mark the correct option.

Question: If the price of petrol goes up by 20%, by what percentage should the consumption be reduced so that the expenditure remains the same?

• I.Price of petrol per litre was Rs. 90
• II.Consumption was 24 litre before price hike

Which one of the following is correct in respect of the above Question and the Statements?

• (a)The Question can be answered by using one of the Statements alone, but cannot be answered using the other Statement alone
• (b)The Question can be answered by using either Statement alone
• (c)The Question can be answered by using both the Statements together, but cannot be answered using either Statement alone
• (d)The Question can be answered even without using any of the Statements

A question is given followed by two statements I and II. Consider the Question and the Statements and mark the correct option.

Question: The ratio of P’s salary to Q’s salary is 6:5. How much is P’s expenditure?

• I.The ratio of P’s saving to Q’s saving is 3:2
• II.The ratio of P’s expenditure to Q’s expenditure is 1:1

Which one of the following is correct in respect of the above Question and the Statements?

• (a)The Question can be answered by using one of the Statements alone, but cannot be answered using the other Statement alone
• (b)The Question can be answered by using either Statement alone
• (c)The Question can be answered by using both the Statements together, but cannot be answered using either Statement alone
• (d)The Question cannot be answered even by using both the Statements together

A question is given followed by two statements I and II. Consider the Question and the Statements and mark the correct option.

Question: The largest of five different integers is 8 and least is 2. What is the average of these integers?

• I.The sum of all the 5 integers is a multiple of 5
• II.The number of odd integers is odd

Which one of the following is correct in respect of the above Question and the Statements?

• (a)The Question can be answered by using one of the Statements alone, but cannot be answered using the other Statement alone
• (b)The Question can be answered by using either Statement alone
• (c)The Question can be answered by using both the Statements together, but cannot be answered using either Statement alone
• (d)The Question cannot be answered even by using both the Statements together

A question is given followed by two statements I and II. Consider the Question and the Statements and mark the correct option.

Question: There are three different weights. All the weights are integers and their sum is a prime number. What are the weights?

• I.One of the weights is twice the another weight
• II.One of the weights is thrice the another weight

Which one of the following is correct in respect of the above Question and the Statements?

• (a)The Question can be answered by using one of the Statements alone, but cannot be answered using the other Statement alone
• (b)The Question can be answered by using either Statement alone
• (c)The Question can be answered by using both the Statements together, but cannot be answered using either Statement alone
• (d)The Question cannot be answered even by using both the Statements together

A question is given followed by two statements I and II. Consider the Question and the Statements and mark the correct option.

Question: What is the amount at the end of 10 years?

• I.The principal amount is ₹1,00,000
• II.Rate of interest is 10% per annum

Which one of the following is correct in respect of the above Question and the Statements?

• (a)The Question can be answered by using one of the Statements alone, but cannot be answered using the other Statement alone
• (b)The Question can be answered by using either Statement alone
• (c)The Question can be answered by using both the Statements together, but cannot be answered using either Statement alone
• (d)The Question cannot be answered even by using both the Statements together

A question is given followed by two statements I and II. Consider the Question and the Statements and mark the correct option.

Question: Is p² + pq + q² odd where p, q are integers?

• I.p+q is even
• II.pq is odd

Which one of the following is correct in respect of the above Question and the Statements?

• (a)The Question can be answered by using one of the Statements alone, but cannot be answered using the other Statement alone
• (b)The Question can be answered by using either Statement alone
• (c)The Question can be answered by using both the Statements together, but cannot be answered using either Statement alone
• (d)The Question cannot be answered even by using both the Statements together

The total population of an area is 10,000 out of which males and females are equal in number. Out of the total population 30% are Newspaper readers. Out of the total newspaper readers, one-third read English Newspaper. Out of the total English Newspaper readers, 20% are females. What is the number of males who do not read English Newspaper?

• (a)800
• (b)2100
• (c)4200
• (d)Cannot be determined due to insufficient data

What is the maximum area of a rectangle, in square cm, whose perimeter is 400 cm?

• (a)100
• (b)200
• (c)1000
• (d)10,000

What is the remainder if we divide 3¹⁰ by 7?

• (a)0
• (b)1
• (c)2
• (d)4

What is the square root of 64%?

• (a)0.08%
• (b)0.8%
• (c)8%
• (d)80%

The difference of 10³¹ – 5 and 10³⁰ + p is divisible by 3 where p is a digit. How many values of p are possible?

• (a)4
• (b)3
• (c)2
• (d)1

Consider the following statements:
I. 61 divides 107¹⁰⁰ – 76¹⁰⁰
II. 100 divides 67⁵ + 33⁵
Which of the statements given above is/are correct?

• (a)I only
• (b)II only
• (c)Both I and II
• (d)Neither I nor II

The average of the temperatures recorded at noontime from Monday to Sunday is 31°C. If the lowest temperature recorded is 30°C, then what is the maximum of temperature that is possible to record at noontime on any one of the days?

• (a)34°C
• (b)35°C
• (c)36°C
• (d)37°C

If (x + 1/yz) – (y + 1/zx) = (y + 1/zx) – (z + 1/xy) and x+z ≠ 2y, then what is xyz equal to?

• (a)-3
• (b)-1
• (c)1
• (d)3

Consider the following statements in respect of p = n(n+1)(n+2)(n+3) + 1, where n is a natural number:
I. p is always odd
II. p is a perfect square
Which of the statements given above is/are correct?

• (a)I only
• (b)II only
• (c)Both I and II
• (d)Neither I nor II

What is the difference between the average of first 50 even natural numbers and the average of first 50 odd natural numbers?

• (a)0
• (b)0.5
• (c)1
• (d)2

Three amounts x, y, z are such that y is the compound interest on x; and z is the compound interest on y. The rate of interest per annum and the time period in years are same. Which one of the following is correct?

• (a)x² = yz
• (b)y² = zx
• (c)z² = xy
• (d)x = yz

There are n concentric squares. The area of the innermost square is 1 unit and the distance between corresponding corners of any two consecutive squares is 1 unit. Consider the following statements:
I. The diagonal of the nth square is 2n + √2 – 2
II. The area included between nth square and (n-1)th square is independent of n
Which of the statements given above is/are correct?

• (a)I only
• (b)II only
• (c)Both I and II
• (d)Neither I nor II

In a rectangle ABCD, AC is one of the diagonals. If AC + AB = 3AD and AC – AD = 4 units, then what is the area of the triangle?

• (a)24 square unit
• (b)36 square unit
• (c)48 square unit
• (d)72 square unit

The area of the circle circumscribing three identical circles touching each other is π(2+√3)²/3 square cm. What is the radius of one of the smaller circles?

• (a)0.5 cm
• (b)1 cm
• (c)1.5 cm
• (d)√3 cm

In a triangle ABC, AB = 21 cm, BC = 20 cm and CA = 13 cm. A perpendicular CD is drawn upon the longest side. What is the area of the triangle BCD?

• (a)96 square cm
• (b)84 square cm
• (c)80 square cm
• (d)72 square cm

There are two containers A and B. In container A, the ratio of milk and water is 1:3 and in container B, the ratio of milk and water is m:n. If the mixture in the containers A and B are mixed in the ratio 2:3 to get 20 litres of a mixture having milk and water in the ratio 3:7, then what is the value of m/n?

• (a)1/2
• (b)2/3
• (c)3/4
• (d)4/5

A cone, a hemisphere and a cylinder stand on equal base of radius r and have the same height. If the sum of volumes of cone, the hemisphere and the cylinder is equal to volume of a sphere of radius R, then what is R³/r³ equal to?

• (a)1.25
• (b)1.5
• (c)2
• (d)2.5

If x³ + px² + qx + r is an integer for all integral values of x, then consider the following statements:
I. p must be an integer
II. q must be an integer
III. r must be an integer
Which of the statements given above is/are correct?

• (a)I and II only
• (b)III only
• (c)I, II and III
• (d)None of the statements is correct

XYZ is a 3-digit number, where X, Y, Z are distinct non-zero digits. The difference between the two 3-digit numbers XYZ and YXZ is 90. How many possible values exist for the sum (X+Y)?

• (a)9
• (b)8
• (c)7
• (d)6

How many times does the minute hand of a clock coincide with the second hand between 2.01 pm and 4.01 pm on the same day?

• (a)121
• (b)120
• (c)119
• (d)None of the above

What is the HCF of 2³⁶-1 and 2⁴⁵-1?

• (a)1023
• (b)512
• (c)511
• (d)255

The section of a solid right circular cone by a plane containing vertex and perpendicular to base is an equilateral triangle of side 14 cm. What is the volume of the cone? (π = 22/7)

• (a)1078√3 cubic cm
• (b)1078/√3 cubic cm
• (c)539√3 cubic cm
• (d)539/√3 cubic cm

Three identical cones each with base radius 3 cm are placed on their bases so that each is touching the other two. There will be one and only circle that would pass through each of the vertices of the cones. What is the area of the circle?

• (a)3π square cm
• (b)6π square cm
• (c)9π square cm
• (d)12π square cm

A circle is inscribed in a triangle ABC right-angled at B. If AB = 5 cm and BC = 12 cm, then what is the radius of the circle?

• (a)1 cm
• (b)1.5 cm
• (c)2 cm
• (d)2.5 cm

The ratio of sum of interior angles to sum of exterior angles of a regular polygon of n sides is 7/2. What is the measure of an interior angle of polygon?

• (a)110°
• (b)120°
• (c)130°
• (d)140°

The number 199 can be written as m²-n², where m, n are natural numbers (m > n). What is the value of mn?

• (a)9900
• (b)9800
• (c)9701
• (d)Cannot be uniquely determined

How many numbers of the form 2ⁿ – 1 and less than 2000 are prime?

• (a)3
• (b)4
• (c)5
• (d)6

In a class of 160 students, each of them opt at least one language from among English, Hindi and Sanskrit. It is found that 130 students opt English, 120 students Hindi and 110 Sanskrit. If the students opt either only one language or all three languages, then what is the number of students who study all three languages?

• (a)40
• (b)60
• (c)80
• (d)100

Let S = 5^a + 7^b + 11^c + 13^d, where a, b, c and d are natural numbers. What is the number of distinct remainders of S when it is divided by 10?

• (a)1
• (b)4
• (c)5
• (d)More than 5

In a right triangle ABC, ∠A = 90° and AD is perpendicular to BC. If ∠CAD = 60° and BC = 6 cm, then what is AB equal to?

• (a)3 cm
• (b)4 cm
• (c)5 cm
• (d)6 cm