WAEC Past Questions and Answers - Page 3921

19,601.

Find the volume (in cm\(^3\)) of the solid shown above

A.

100cm3

B.

150cm3

C.

175cm3

D.

250cm3

Correct answer is C

Total volume = (5 x 5) x 5 + (5 x 5) x 2 

= 125 + 50 

= 175 cm\(^3\)

19,602.

The area of a circle is 38.5cm2. Find its diameter [take \(\pi = \frac{22}{7}\)]

A.

22cm

B.

14cm

C.

7cm

D.

6cm

Correct answer is C

\(\pi r^2 = 38.5\\
\frac{}{} = r^2 = 38.5\\
r^2 = \frac{38.5 \times 7}{22}\\
r = \sqrt{12.25} = 3.5\\
diameter = 2r = 2 \times 3.5 = 7cm\)

19,603.

In the diagram, |PQ| = |PS| Which of the following statements is true?

A.

∠QPS = QRS

B.

|PO| = |RO|

C.

QR||PS

D.

∠PQR=∠PSR

Correct answer is D

No explanation has been provided for this answer.

19,604.

The arc of a circle 50 cm long, subtends angle of 75° at the center of the circle. Find correct to 3 significant figures, the radius of the circle. Take \(\pi = \frac{22}{7}\)

A.

8.74cm

B.

38.2cm

C.

61.2cm

D.

76.4cm

Correct answer is B

Length of arc = \(\frac{\theta}{360} \times 2\pi r\)

\(50 = \frac{75}{360} \times 2 \times \frac{22}{7} \times r\)

\(r = \frac{50 \times 360 \times 7}{75 \times 2 \times 22}\)

\(r = \frac{420}{11}\)

= 38.18 cm \(\approxeq\) 38.2 cm (3 sig. figs)

19,605.

The length of the parallel sides of a trapezium are 5cm and 7cm. If its area is 120cm\(^2\), find the perpendicular distance between the parallel sides

A.

5.0cm

B.

6.9cm

C.

10.0cm

D.

20.0cm

Correct answer is D

Area of trapezium = \(\frac{1}{2} (a + b)h\)

\(120 = \frac{1}{2} (5 + 7) \times h\)

\(120 = 6h\)

\(h = 20 cm\)