WAEC Mathematics Past Questions & Answers - Page 312

1,556.

Find the area of the enclosed region, PXROY correct to the nearest whole number

96cm²

116cm²

154cm²

192cm²

385cm²

View answer & explanation

Correct answer is A

Area of the bigger semi circle P x RO =

πr²/2

22/7

49/2

= 77cm²

2nd Area of the smaller circle DYO =

22/7

3.5²/2

= 19.25

Total Area = 77 + 19.25 = 96.25 = 96.00

1,557.

Mrs. Kofi sold an article for C7.50 instead of C12.75. Calculate her percentage of error, correct to one decimal place.

41.2%

18.3%

5.3%

1.7%

1.4%

View answer & explanation

Correct answer is A

Error =12.75 - 7.50 = 5.25

Error % = \(\frac{5.25}{12.75}\) x 100% = 41.2%

1,558.

A car is travelling at an average speed of 80km/hr. Its speed in meters per second (m/s) is

13.3m/s

22.2m/s

133.3m/s

222.2m/s

1333.3m/s

View answer & explanation

Correct answer is B

80km/h = \(\frac{80}{60}\) x \(\frac{1000}{60}\) = 3 x 3= \(\frac{40 x 5}{9}\)

= \(\frac{200m/s}{9}\) = 22.22m/s

1,559.

A headmaster contributes 7% of his income into a fund and his wife contributes 4% of her income. If the husband earns N5,500 per annum (p.a) and the wife earns N4,000 (P.a), find the sum of their annual contribution to the fund

N1045

N605

N545

N490

N440

View answer & explanation

Correct answer is C

Husband contributions = \(\frac{7}{100}\) x N5,500 = N385

Wife contribution = \(\frac{4}{100}\) x N4,000 = N160

Sum of their Annual contribution = N385 + N160 = N545

1,560.

A cylinder of base radius 4cm is open at one end . If the ratio of the area of its base to that of its curved surface is 1:4, calculate the height of the cylinder

1cm

2cm

4cm

8cm

16cm

View answer & explanation

Correct answer is D

r= 4cm; base area = \(\pi\)r²; Curve S.A = 2\(\pi\)rh

\(\frac{base area}{curved area}\) = 1/4; \(\pi\)/2\(\pi\)rh

=h = \(\frac{4 x 4cm}{2}\)

h= 8cm