Year : 
2011
Title : 
Mathematics (Core)
Exam : 
WASSCE/WAEC MAY/JUNE

Paper 1 | Objectives

1 - 10 of 49 Questions

# Question Ans
1.

If N112.00 exchanges for D14.95, calculate the value of D1.00 in naira

A. 0.13

B. 7.49

C. 8.00

D. 13.00

Detailed Solution

D14.95 = N112.00

D1.00 = \(\frac{N112}{D14.95} \times\) D1.00

= 7.49
2.

Solve for x in the equation; \(\frac{3}{5}\)(2x - 1) = \(\frac{1}{4}\)(5x - 3)

A. zero

B. 1

C. 2

D. 3

Detailed Solution

\(\frac{3}{5}\)(2x - 1) = \(\frac{1}{4}\)(5x - 3)

\(\frac{6x}{5} - \frac{3}{5} = \frac{5x}{4} - \frac{3}{4}\)

\(\frac{6x}{5} - \frac{5x}{4} = \frac{3}{5} - \frac{3}{4}\)

\(\frac{24x - 25x}{20} = \frac{12 - 15}{20}\)

\(\frac{-x}{20} = \frac{-3}{20}\)

-20x = -60

x = \(\frac{-60}{-20}\)

x = 3
3.

Given that cos xo = \(\frac{1}{r}\), express tan x in terms of r

A. \(\frac{1}{\sqrt{r}}\)

B. \(\sqrt{r}\)

C. \(\sqrt{r^2 + 1}\)

D. \(\sqrt{r^2 - 1}\)

Detailed Solution

cos xo = \(\frac{1}{r}\); \(\sqrt{r^2 - 1}\)

By Pythagoras r2 = 12 + x2 - 1

x = \(\sqrt{r^2 - 1}\)

tan xo = \(\sqrt{r^2 - 1}\)

= \(\sqrt{r^2 - 1}\)
4.

Solve the equation; 3x - 2y = 7, x + 2y = -3

A. x = 1, y = -2

B. x = 1, y = 3

C. x = -2, y = -1

D. x = 4, y = -3

Detailed Solution

3x - 2y = 7; Solve by elimination method

x + 2y = -3

3x - 2y = 7.....(i)

-3x + 6y = -9.....(ii)

-8y = 16

y = \(\frac{16}{-8} = -2\)

Put y = -2 into equation (i); 3x - 2y = 7

3x - 2(-2) = 7

3x + 4 = 7

3x = 7 - 4

3x = 3

x = \(\frac{3}{3}\) = 1
5.

If a number is chosen at random from the set {x: 4 \(\leq x \leq 15\)}. Find the probability that it is a multiple of 3 or a multiple of 4

A. \(\frac{1}{12}\)

B. \(\frac{5}{12}\)

C. \(\frac{7}{12}\)

D. \(\frac{11}{12}\)

Detailed Solution

set = 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15

multiple of 3 = 6, 9, 12, 15

multiple of 4 = 4, 8, 12

Prob(multiple of 3 or 4) = Prob(multiple of 3) + pro(multiple of 4)

= \(\frac{4}{12} + \frac{3}{12} = \frac{7}{12}\)
6.

One of the factors of (mn - nq - n2 + mq) is (m - n). The other factor is?

A. (n - q)

B. (q - n)

C. (n + q)

D. (q - m)

Detailed Solution

mn - nq - n\(^2\) + mq

mn - n\(^2\) - nq + mq

(mn - n\(^2\)) (mq - nq)

n(m - n) + q(m - n)

= (n +q) (m - n)
7.

A cylindrical container has a base radius of 14cm and height 18cm. How many litres of liquid can it hold? correct to the nearest litre [Take \(\pi = \frac{22}{7}\)]

A. 11

B. 14

C. 16

D. 18

Detailed Solution

Volume of cylinder = \(\pi r^2 h\)

= \(\frac{22}{7} \times 14^2\) x 14 x 18 = 22 x 28 x 18

= 11088cm3

1000cm3 = \(\frac{1}{1000}\) x 11088cm3

= 11.088

= 11
8.

A regular polygon of n sides has each exterior angle to 45o. Find the value of n

A. 6

B. 8

C. 12

D. 15

Detailed Solution

Each interior angle = \(\frac{360^o}{n}\)

45o = \(\frac{360^o}{n}\)

45on = 360o

n = \(\frac{360^o}{45}\)

= 8
9.

Esther was facing S 20° W. She turned 90° in the clock wise direction. What direction is she facing?

A. N 70o W

B. S 70o W

C. N 20o W

D. S 20o E

Detailed Solution

The bearing S 20° W is equivalent to a bearing of 200°.
Moving clockwise 90° ⇒ 200° + 90°
= 290°
This is equivalent to N 70° W.
10.

The cross section section of a uniform prism is a right-angled triangle with sides 3cm. 4cm and 5cm. If its length is 10cm. Calculate the total surface area

A. 142cm2

B. 132cm2

C. 122cm2

D. 112cm2

Detailed Solution

A prism has 3 rectangular faces and 2 triangular faces and 2 rectangular faces = 10(3 + 4 + 5) = 120

Area of triangular faces = \(\sqrt{s(s - a) (s - b) (s - c)}\)

where s = \(\frac{a + b + c}{2}\)

= \(\frac{3 + 4 + 5}{2}\)

= \(\frac{12}{2}\)

= 6

Area of \(\bigtriangleup\) = \(\sqrt{6(6 - 30(6 - 4)(6 - 5)}\)

= \(\sqrt{6 \times 3 \times 2 \times 1}\) = 6

Area of triangle faces = 2 x 6 = 12cm2

Total surface area = Area of rectangular face + Area of \(\bigtriangleup\) = 120 + 12

= 132cm2 &
1.

If N112.00 exchanges for D14.95, calculate the value of D1.00 in naira

A. 0.13

B. 7.49

C. 8.00

D. 13.00

Detailed Solution

D14.95 = N112.00

D1.00 = \(\frac{N112}{D14.95} \times\) D1.00

= 7.49
2.

Solve for x in the equation; \(\frac{3}{5}\)(2x - 1) = \(\frac{1}{4}\)(5x - 3)

A. zero

B. 1

C. 2

D. 3

Detailed Solution

\(\frac{3}{5}\)(2x - 1) = \(\frac{1}{4}\)(5x - 3)

\(\frac{6x}{5} - \frac{3}{5} = \frac{5x}{4} - \frac{3}{4}\)

\(\frac{6x}{5} - \frac{5x}{4} = \frac{3}{5} - \frac{3}{4}\)

\(\frac{24x - 25x}{20} = \frac{12 - 15}{20}\)

\(\frac{-x}{20} = \frac{-3}{20}\)

-20x = -60

x = \(\frac{-60}{-20}\)

x = 3
3.

Given that cos xo = \(\frac{1}{r}\), express tan x in terms of r

A. \(\frac{1}{\sqrt{r}}\)

B. \(\sqrt{r}\)

C. \(\sqrt{r^2 + 1}\)

D. \(\sqrt{r^2 - 1}\)

Detailed Solution

cos xo = \(\frac{1}{r}\); \(\sqrt{r^2 - 1}\)

By Pythagoras r2 = 12 + x2 - 1

x = \(\sqrt{r^2 - 1}\)

tan xo = \(\sqrt{r^2 - 1}\)

= \(\sqrt{r^2 - 1}\)
4.

Solve the equation; 3x - 2y = 7, x + 2y = -3

A. x = 1, y = -2

B. x = 1, y = 3

C. x = -2, y = -1

D. x = 4, y = -3

Detailed Solution

3x - 2y = 7; Solve by elimination method

x + 2y = -3

3x - 2y = 7.....(i)

-3x + 6y = -9.....(ii)

-8y = 16

y = \(\frac{16}{-8} = -2\)

Put y = -2 into equation (i); 3x - 2y = 7

3x - 2(-2) = 7

3x + 4 = 7

3x = 7 - 4

3x = 3

x = \(\frac{3}{3}\) = 1
5.

If a number is chosen at random from the set {x: 4 \(\leq x \leq 15\)}. Find the probability that it is a multiple of 3 or a multiple of 4

A. \(\frac{1}{12}\)

B. \(\frac{5}{12}\)

C. \(\frac{7}{12}\)

D. \(\frac{11}{12}\)

Detailed Solution

set = 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15

multiple of 3 = 6, 9, 12, 15

multiple of 4 = 4, 8, 12

Prob(multiple of 3 or 4) = Prob(multiple of 3) + pro(multiple of 4)

= \(\frac{4}{12} + \frac{3}{12} = \frac{7}{12}\)
6.

One of the factors of (mn - nq - n2 + mq) is (m - n). The other factor is?

A. (n - q)

B. (q - n)

C. (n + q)

D. (q - m)

Detailed Solution

mn - nq - n\(^2\) + mq

mn - n\(^2\) - nq + mq

(mn - n\(^2\)) (mq - nq)

n(m - n) + q(m - n)

= (n +q) (m - n)
7.

A cylindrical container has a base radius of 14cm and height 18cm. How many litres of liquid can it hold? correct to the nearest litre [Take \(\pi = \frac{22}{7}\)]

A. 11

B. 14

C. 16

D. 18

Detailed Solution

Volume of cylinder = \(\pi r^2 h\)

= \(\frac{22}{7} \times 14^2\) x 14 x 18 = 22 x 28 x 18

= 11088cm3

1000cm3 = \(\frac{1}{1000}\) x 11088cm3

= 11.088

= 11
8.

A regular polygon of n sides has each exterior angle to 45o. Find the value of n

A. 6

B. 8

C. 12

D. 15

Detailed Solution

Each interior angle = \(\frac{360^o}{n}\)

45o = \(\frac{360^o}{n}\)

45on = 360o

n = \(\frac{360^o}{45}\)

= 8
9.

Esther was facing S 20° W. She turned 90° in the clock wise direction. What direction is she facing?

A. N 70o W

B. S 70o W

C. N 20o W

D. S 20o E

Detailed Solution

The bearing S 20° W is equivalent to a bearing of 200°.
Moving clockwise 90° ⇒ 200° + 90°
= 290°
This is equivalent to N 70° W.
10.

The cross section section of a uniform prism is a right-angled triangle with sides 3cm. 4cm and 5cm. If its length is 10cm. Calculate the total surface area

A. 142cm2

B. 132cm2

C. 122cm2

D. 112cm2

Detailed Solution

A prism has 3 rectangular faces and 2 triangular faces and 2 rectangular faces = 10(3 + 4 + 5) = 120

Area of triangular faces = \(\sqrt{s(s - a) (s - b) (s - c)}\)

where s = \(\frac{a + b + c}{2}\)

= \(\frac{3 + 4 + 5}{2}\)

= \(\frac{12}{2}\)

= 6

Area of \(\bigtriangleup\) = \(\sqrt{6(6 - 30(6 - 4)(6 - 5)}\)

= \(\sqrt{6 \times 3 \times 2 \times 1}\) = 6

Area of triangle faces = 2 x 6 = 12cm2

Total surface area = Area of rectangular face + Area of \(\bigtriangleup\) = 120 + 12

= 132cm2 &