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

Paper 1 | Objectives

11 - 20 of 49 Questions

# Question Ans
11.

From the equation whose roots are x = \(\frac{1}{2}\) and -\(\frac{2}{3}\)

A. 6x2 - x + 2 = 0

B. 6x2 - x - 2 = 0

C. 6x2 + x + 2 = 0

D. 6x2 + x - 2 = 0

Detailed Solution

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

expand (x - \(\frac{1}{2}\))(x + \(\frac{2}{3}\)) = 0

x(x + \(\frac{2}{3}\)) - \(\frac{1}{2}(x + \frac{2}{3}\)) = 0

x2 + \(\frac{4x - 3x}{6} - \frac{2}{6} = 0\)

\(x^2 + \frac{x}{6} - 2 = 0\)

6x2 + x - 2 = 0
12.

Simplify \(\frac{\log \sqrt{27}}{\log \sqrt{81}}\)

A. 3

B. 2

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

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

Detailed Solution

\(\frac{\log \sqrt{27}}{\log \sqrt{81}}\) = \(\frac{\log 27\frac{1}{2}}{81\frac{1}{2}}\)

= \(\frac{\log 3\frac{1}{2}}{\log 3^2}\)

\(\frac{\frac{3}{2} \log 3}{2 \log 3} = \frac{3}{2} \div \frac{2}{1}\)

= \(\frac{3}{2} \times \frac{1}{2}\)

= \(\frac{3}{4}\)
13.

Which of these angles can be constructed using ruler and a pair of compasses only?

A. 115o

B. 125o

C. 135o

D. 145o

C

14.

The perimeter of a sector of a circle of radius 4cm is (\(\pi + 8\))cm. Calculate the anle of the sector

A. 45o

B. 60o

C. 75o

D. 90o

Detailed Solution

Perimeter of sector = 2r + \(\frac{\theta}{360^o} \times 2\pi r\)

\(\pi + 8 = 2 \times 4 + \frac{\theta}{3360^o} \times 2 \pi \times 4\)

\(\pi + 8 + \frac{\theta}{360^o} \times 8 \pi\)

P + 8 - 8 = \(\frac{\theta \pi}{456o}\)

\(\pi = \frac{\theta \pi}{45^o}\)

\(\theta \pi = 45^o\)
15.

The length of a piece of stick is 1.75m. A girl measured it as 1.80m. Find the percentage error

A. \(\frac{28}{7}\)%

B. \(\frac{29}{7}\)%

C. 5%

D. \(\frac{20}{7}\)%

Detailed Solution

Error = 1.80m - 1.75m = 0.05m

%error = \(\frac{\text{error}}{\text{true measurement}}\) x 100%
16.

What is the value of 3 in the number 42.7531?

A. \(\frac{3}{10000}\)

B. \(\frac{3}{1000}\)

C. \(\frac{3}{100}\)

D. \(\frac{1}{10}\)

B

17.

The height of a cylinder is equal to its radius. If the volume is 0.216 \(\pi\) m\(^3\). Calculate the radius.

A. 0.46m

B. 0.60m

C. 0.87m

D. 1.80m

Detailed Solution

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

0.216\(\pi\) m\(^3\) = \(\pi \times r^2 \times h\)

Since r = h,

0.216 = r\(^3\)

r\(^3\) = 0.216

r = \(\sqrt[3]{0.216}\)

= 0.6
18.

The height of a cylinder is equal to its radius. If the volume is 0.216 \(\pi m^3\) Calculate the radius.

A. 0.46m

B. 0.60m

C. 0.87m

D. 1.80m

Detailed Solution

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

0.216\(\pi m^3 = \pi \times r^2 \times 1m\)

assumed that h = 1m

0.216 = r2

r2 = 0.216

r = \(\sqrt{0.216}\)

= 0.46
19.

What is the value of 3 in the number 42.7531?

A. \(\frac{3}{10000}\)

B. \(\frac{3}{1000}\)

C. \(\frac{3}{100}\)

D. \(\frac{1}{10}\)

B

20.

Factorize the expression: am + bn - an - bm

A. (a - b)(m + n)

B. (a - b)(m - n)

C. (a + b)(m - n)

D. (a + b)(m + n)

Detailed Solution

am + bn - an - bm

am - an - bm + bn

a(m - n) - b(m - n)

(a - b)(m - n)
11.

From the equation whose roots are x = \(\frac{1}{2}\) and -\(\frac{2}{3}\)

A. 6x2 - x + 2 = 0

B. 6x2 - x - 2 = 0

C. 6x2 + x + 2 = 0

D. 6x2 + x - 2 = 0

Detailed Solution

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

expand (x - \(\frac{1}{2}\))(x + \(\frac{2}{3}\)) = 0

x(x + \(\frac{2}{3}\)) - \(\frac{1}{2}(x + \frac{2}{3}\)) = 0

x2 + \(\frac{4x - 3x}{6} - \frac{2}{6} = 0\)

\(x^2 + \frac{x}{6} - 2 = 0\)

6x2 + x - 2 = 0
12.

Simplify \(\frac{\log \sqrt{27}}{\log \sqrt{81}}\)

A. 3

B. 2

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

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

Detailed Solution

\(\frac{\log \sqrt{27}}{\log \sqrt{81}}\) = \(\frac{\log 27\frac{1}{2}}{81\frac{1}{2}}\)

= \(\frac{\log 3\frac{1}{2}}{\log 3^2}\)

\(\frac{\frac{3}{2} \log 3}{2 \log 3} = \frac{3}{2} \div \frac{2}{1}\)

= \(\frac{3}{2} \times \frac{1}{2}\)

= \(\frac{3}{4}\)
13.

Which of these angles can be constructed using ruler and a pair of compasses only?

A. 115o

B. 125o

C. 135o

D. 145o

C

14.

The perimeter of a sector of a circle of radius 4cm is (\(\pi + 8\))cm. Calculate the anle of the sector

A. 45o

B. 60o

C. 75o

D. 90o

Detailed Solution

Perimeter of sector = 2r + \(\frac{\theta}{360^o} \times 2\pi r\)

\(\pi + 8 = 2 \times 4 + \frac{\theta}{3360^o} \times 2 \pi \times 4\)

\(\pi + 8 + \frac{\theta}{360^o} \times 8 \pi\)

P + 8 - 8 = \(\frac{\theta \pi}{456o}\)

\(\pi = \frac{\theta \pi}{45^o}\)

\(\theta \pi = 45^o\)
15.

The length of a piece of stick is 1.75m. A girl measured it as 1.80m. Find the percentage error

A. \(\frac{28}{7}\)%

B. \(\frac{29}{7}\)%

C. 5%

D. \(\frac{20}{7}\)%

Detailed Solution

Error = 1.80m - 1.75m = 0.05m

%error = \(\frac{\text{error}}{\text{true measurement}}\) x 100%
16.

What is the value of 3 in the number 42.7531?

A. \(\frac{3}{10000}\)

B. \(\frac{3}{1000}\)

C. \(\frac{3}{100}\)

D. \(\frac{1}{10}\)

B

17.

The height of a cylinder is equal to its radius. If the volume is 0.216 \(\pi\) m\(^3\). Calculate the radius.

A. 0.46m

B. 0.60m

C. 0.87m

D. 1.80m

Detailed Solution

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

0.216\(\pi\) m\(^3\) = \(\pi \times r^2 \times h\)

Since r = h,

0.216 = r\(^3\)

r\(^3\) = 0.216

r = \(\sqrt[3]{0.216}\)

= 0.6
18.

The height of a cylinder is equal to its radius. If the volume is 0.216 \(\pi m^3\) Calculate the radius.

A. 0.46m

B. 0.60m

C. 0.87m

D. 1.80m

Detailed Solution

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

0.216\(\pi m^3 = \pi \times r^2 \times 1m\)

assumed that h = 1m

0.216 = r2

r2 = 0.216

r = \(\sqrt{0.216}\)

= 0.46
19.

What is the value of 3 in the number 42.7531?

A. \(\frac{3}{10000}\)

B. \(\frac{3}{1000}\)

C. \(\frac{3}{100}\)

D. \(\frac{1}{10}\)

B

20.

Factorize the expression: am + bn - an - bm

A. (a - b)(m + n)

B. (a - b)(m - n)

C. (a + b)(m - n)

D. (a + b)(m + n)

Detailed Solution

am + bn - an - bm

am - an - bm + bn

a(m - n) - b(m - n)

(a - b)(m - n)