Year : 
2014
Title : 
Mathematics (Core)
Exam : 
WASSCE/WAEC MAY/JUNE

Paper 1 | Objectives

21 - 30 of 49 Questions

# Question Ans
21.

If x : y = 3 : 2 and y : z = 5 : 4, find the value of x in the ratio x : y : z

A. 8

B. 10

C. 15

D. 20

C

22.

Given that cos x = \(\frac{12}{13}\), evaluate \(\frac{1 - \tan x}{\tan x}\)

A. \(\frac{5}{13}\)

B. \(\frac{5}{7}\)

C. \(\frac{7}{5}\)

D. \(\frac{13}{5}\)

Detailed Solution

cos x\(\frac{12}{13}\)

132 = 122 + a2

169 = 144 + a2

a2 = 169 - 144

a2 = 25

a \(\sqrt{25}\)

a = 5

tan x = \(\frac{5}{12}\)

\(\frac{1 - \tan x}{\tan x} = \frac{1 - \frac{5}{12}}{\frac{5}{12}}\)

\(\frac{\frac{1 - \frac{5}{12}}{12 - 5}}{12} = \frac{\frac{7}{12}}{\frac{5}{12}}\)

= \(\frac{7}{2} \div \frac{5}{12}\)

= \(\frac{7}{12} \times \frac{12}{5} = \frac{7}{5}\)
23.

Approximate 0.0033780 to 3 significant figures

A. 338

B. 0.338

C. 0.00338

D. 0.003

C

24.

Simplify \(\frac{\sqrt{8^2 \times 4^{n + 1}}}{2^{2n} \times 16}\)

A. 16

B. 8

C. 4

D. 1

Detailed Solution

\(\frac{\sqrt{8^2 \times 4^{n + 1}}}{2^{2n} \times 16}\)

= \(\frac{\sqrt{2^{3(2)} \times 2^{2(n + 1)}}}{2^{2n} \times 2^4}\)

= \(\frac{\sqrt{2^6 \times 2^{2n + 2)}}}{2^{2n} + 4}\)

= \(\frac{\sqrt{2^6 + 2^{2n + 2)}}}{2^{2n} + 4}\)

= \(\frac{\sqrt{2^{2n + 8}}}{2^{2n} + 4}\)

= \(\sqrt{2^{2n + 8} \div 2^{2n} + 4}\)

= \(\sqrt{2^{2n - 2n} + 8 - 4}\)

= \(\sqrt{2^4}\)

= \(\sqrt{16}\)

= 4
25.

If \(\frac{2}{x - 3} - \frac{3}{x - 2}\) is equal to \(\frac{p}{(x - 3)(x - 2)}\), find p

A. -x - 5

B. -(x + 3)

C. 5x - 13

D. 5 - x

Detailed Solution

\(\frac{2}{x - 3} - \frac{3}{x - 2}\) = \(\frac{p}{(x - 3)(x - 2)}\)

\(\frac{2(x - 2) - 3(x - 3)}{(x - 3)(x - 2)}\) = \(\frac{p}{(x - 3)(x - 2)}\)

= \(\frac{2x - 4 - 3x + 9}{(x - 3)(x - 2)}\) = \(\frac{p}{(x - 3)(x - 2)}\)

\(\frac{-x + 5}{(x - 3)(x - 2)} = \frac{p}{(x - 3)(x - 2)}\)

p(x - 3)(x - 2) = -x + 5(x - 3)(x - 2)

p = -x + 5 or p = 5 - x
26.

Subtract \(\frac{1}{2}\)(a - b - c) from the sum of \(\frac{1}{2}\)(a - b + c) and \(\frac{1}{2}\)
(a + b - c)

A. \(\frac{1}{2}\) (a + b + c)

B. \(\frac{1}{2}\) (a - b - c)

C. \(\frac{1}{2}\) (a - b + c)

D. \(\frac{1}{2}\) (a + b - c)

Detailed Solution

\(\frac{1}{2}\)(a - b + c) + \(\frac{1}{2}\)(a + b - c) - [\(\frac{1}{2}\) (a - b - c)]

\(\frac{1}{2}a - \frac{1}{2}b + \frac{1}{2}c + \frac{1}{2}a + \frac{1}{2}b - \frac{1}{2}c - \frac{1}{2}a + \frac{1}{2}b + \frac{1}{2}c\)

= \(\frac{1}{2}a + \frac{1}{2}b + \frac{1}{2}c\)

= \(\frac{1}{2}(a + b + c)\)
27.

A man's eye level is 1.7m above the horizontal ground and 13m from a vertical pole. If the pole is 8.3m high, calculate, correct to the nearest degree, the angle of elevation of the top of the pole from his eyes.

A. 33o

B. 32o

C. 27o

D. 26o

Detailed Solution

tan \(\theta = \frac{opp}{adj} = \frac{6.6}{13}\)

tan \(\theta = 0.5077\)

\(\theta\) = tan-1 0.5077

\(\theta = 27^o\)
28.

A chord subtends an angle of 120o at the centre of a circle of radius 3.5cm. Find the perimeter of the minor sector containing the chord, [Take \(\pi = \frac{22}{7}\)]

A. 14\(\frac{1}{3}\)cm

B. 12\(\frac{5}{6}\)cm

C. 8\(\frac{1}{7}\)cm

D. 7\(\frac{1}{3}\)cm

Detailed Solution

perimeter of minor sector

2r + \(\frac{\theta}{360} \times 2 \pi r\)

= 2 x 3.5 + \(\frac{120^o}{360^o} \times 2 \frac{22}{7} \times 3.5\)

= 7 + \(\frac{154}{21}\)

= 7 + 7.33

= 14.33

= 14\(\frac{1}{3}\)cm
29.

In parallelogram PQRS, QR is produced to M such that |QR| = |RM|. What fraction of the area of PQMS is the area of PRMS?

A. \(\frac{1}{4}\)

B. \(\frac{1}{3}\)

C. \(\frac{2}{3}\)

D. \(\frac{3}{4}\)

Detailed Solution

There are 3 triangles: \(\bigtriangleup\)MRS, \(\bigtriangleup\) and \(\bigtriangleup\) PRQ

Area PRMS has 2 triangles: \(\bigtriangleup\) MRS and \(\bigtriangleup\) RSP

the fraction = \(\frac{2}{3}\)
30.

In a cumulative frequency graph, the lower quartile is 18 years while the 60th percentile is 48 years. What percentage of the distribution is at most 18 years or greater than 48 years?

A. 15%

B. 35%

C. 65%

D. 85%

C

21.

If x : y = 3 : 2 and y : z = 5 : 4, find the value of x in the ratio x : y : z

A. 8

B. 10

C. 15

D. 20

C

22.

Given that cos x = \(\frac{12}{13}\), evaluate \(\frac{1 - \tan x}{\tan x}\)

A. \(\frac{5}{13}\)

B. \(\frac{5}{7}\)

C. \(\frac{7}{5}\)

D. \(\frac{13}{5}\)

Detailed Solution

cos x\(\frac{12}{13}\)

132 = 122 + a2

169 = 144 + a2

a2 = 169 - 144

a2 = 25

a \(\sqrt{25}\)

a = 5

tan x = \(\frac{5}{12}\)

\(\frac{1 - \tan x}{\tan x} = \frac{1 - \frac{5}{12}}{\frac{5}{12}}\)

\(\frac{\frac{1 - \frac{5}{12}}{12 - 5}}{12} = \frac{\frac{7}{12}}{\frac{5}{12}}\)

= \(\frac{7}{2} \div \frac{5}{12}\)

= \(\frac{7}{12} \times \frac{12}{5} = \frac{7}{5}\)
23.

Approximate 0.0033780 to 3 significant figures

A. 338

B. 0.338

C. 0.00338

D. 0.003

C

24.

Simplify \(\frac{\sqrt{8^2 \times 4^{n + 1}}}{2^{2n} \times 16}\)

A. 16

B. 8

C. 4

D. 1

Detailed Solution

\(\frac{\sqrt{8^2 \times 4^{n + 1}}}{2^{2n} \times 16}\)

= \(\frac{\sqrt{2^{3(2)} \times 2^{2(n + 1)}}}{2^{2n} \times 2^4}\)

= \(\frac{\sqrt{2^6 \times 2^{2n + 2)}}}{2^{2n} + 4}\)

= \(\frac{\sqrt{2^6 + 2^{2n + 2)}}}{2^{2n} + 4}\)

= \(\frac{\sqrt{2^{2n + 8}}}{2^{2n} + 4}\)

= \(\sqrt{2^{2n + 8} \div 2^{2n} + 4}\)

= \(\sqrt{2^{2n - 2n} + 8 - 4}\)

= \(\sqrt{2^4}\)

= \(\sqrt{16}\)

= 4
25.

If \(\frac{2}{x - 3} - \frac{3}{x - 2}\) is equal to \(\frac{p}{(x - 3)(x - 2)}\), find p

A. -x - 5

B. -(x + 3)

C. 5x - 13

D. 5 - x

Detailed Solution

\(\frac{2}{x - 3} - \frac{3}{x - 2}\) = \(\frac{p}{(x - 3)(x - 2)}\)

\(\frac{2(x - 2) - 3(x - 3)}{(x - 3)(x - 2)}\) = \(\frac{p}{(x - 3)(x - 2)}\)

= \(\frac{2x - 4 - 3x + 9}{(x - 3)(x - 2)}\) = \(\frac{p}{(x - 3)(x - 2)}\)

\(\frac{-x + 5}{(x - 3)(x - 2)} = \frac{p}{(x - 3)(x - 2)}\)

p(x - 3)(x - 2) = -x + 5(x - 3)(x - 2)

p = -x + 5 or p = 5 - x
26.

Subtract \(\frac{1}{2}\)(a - b - c) from the sum of \(\frac{1}{2}\)(a - b + c) and \(\frac{1}{2}\)
(a + b - c)

A. \(\frac{1}{2}\) (a + b + c)

B. \(\frac{1}{2}\) (a - b - c)

C. \(\frac{1}{2}\) (a - b + c)

D. \(\frac{1}{2}\) (a + b - c)

Detailed Solution

\(\frac{1}{2}\)(a - b + c) + \(\frac{1}{2}\)(a + b - c) - [\(\frac{1}{2}\) (a - b - c)]

\(\frac{1}{2}a - \frac{1}{2}b + \frac{1}{2}c + \frac{1}{2}a + \frac{1}{2}b - \frac{1}{2}c - \frac{1}{2}a + \frac{1}{2}b + \frac{1}{2}c\)

= \(\frac{1}{2}a + \frac{1}{2}b + \frac{1}{2}c\)

= \(\frac{1}{2}(a + b + c)\)
27.

A man's eye level is 1.7m above the horizontal ground and 13m from a vertical pole. If the pole is 8.3m high, calculate, correct to the nearest degree, the angle of elevation of the top of the pole from his eyes.

A. 33o

B. 32o

C. 27o

D. 26o

Detailed Solution

tan \(\theta = \frac{opp}{adj} = \frac{6.6}{13}\)

tan \(\theta = 0.5077\)

\(\theta\) = tan-1 0.5077

\(\theta = 27^o\)
28.

A chord subtends an angle of 120o at the centre of a circle of radius 3.5cm. Find the perimeter of the minor sector containing the chord, [Take \(\pi = \frac{22}{7}\)]

A. 14\(\frac{1}{3}\)cm

B. 12\(\frac{5}{6}\)cm

C. 8\(\frac{1}{7}\)cm

D. 7\(\frac{1}{3}\)cm

Detailed Solution

perimeter of minor sector

2r + \(\frac{\theta}{360} \times 2 \pi r\)

= 2 x 3.5 + \(\frac{120^o}{360^o} \times 2 \frac{22}{7} \times 3.5\)

= 7 + \(\frac{154}{21}\)

= 7 + 7.33

= 14.33

= 14\(\frac{1}{3}\)cm
29.

In parallelogram PQRS, QR is produced to M such that |QR| = |RM|. What fraction of the area of PQMS is the area of PRMS?

A. \(\frac{1}{4}\)

B. \(\frac{1}{3}\)

C. \(\frac{2}{3}\)

D. \(\frac{3}{4}\)

Detailed Solution

There are 3 triangles: \(\bigtriangleup\)MRS, \(\bigtriangleup\) and \(\bigtriangleup\) PRQ

Area PRMS has 2 triangles: \(\bigtriangleup\) MRS and \(\bigtriangleup\) RSP

the fraction = \(\frac{2}{3}\)
30.

In a cumulative frequency graph, the lower quartile is 18 years while the 60th percentile is 48 years. What percentage of the distribution is at most 18 years or greater than 48 years?

A. 15%

B. 35%

C. 65%

D. 85%

C