WAEC Mathematics Past Questions & Answers - Page 155

771.

A messenger was paid N2.50 an hour during the normal working hours and 4.00 n hour during overtime. If he received N31.00 for 10 hours work, how many hours are for overtime?

A.

2

B.

3

C.

4

D.

6

Correct answer is C

Let normal working hour = x

let overtime = y

after 10 hours = N31.00

1 x 2.50x + 4y = 31

4 x x + y = 10

2.50x + 4y = 31
- 4x + 4y = 30
----------------
-1.5x = -9

x = 6; x + y = 10

6 + y = 10

y = 10 - 4

y = 4hrs for over time

772.

Find the value of a if log\(_{10}\) a + log\(_{10}\)a\(^2\) = 0.9030

A.

4.0

B.

2.0

C.

1.6

D.

0.0

Correct answer is C

log\(_{10}\) a + log\(_{10}\)a\(^2\) = 0.9030

log (a x a\(^2\)) = 0.9030

log a\(^3\) = 0.9030

a\(^3\) = 10^.9030(antilogarithm table)

a\(^3\) = 7.998

a = 3\(\sqrt{7.998}\)

a = 1.6

773.

The bearing of a point P from another point Q is 310o. If |PQ| = 200m, how far west of Q is P?

A.

128.6m

B.

153.2m

C.

167.8m

D.

187.9m

Correct answer is B

cos 40 = \(\frac{x}{200}\)

x - 200 x cosx

= 200 x 0.7660

x = 153.2m

774.

Q is 32 km away from P on a bearing 042o and R is 25km from P on a bearing of 132o. Calculate the bearing of R from Q.

A.

122o

B.

184o

C.

190o

D.

226o

Correct answer is B

No explanation has been provided for this answer.

775.

Divide the sum of 8, 6, 7, 2, 0, 4, 7, 2, 3, by their mean

A.

9

B.

8

C.

7

D.

6

Correct answer is A

Sum = 8 + 6 + 7 + 2 + 0 + 4 + 7 + 2 + 3 = 39

mean = \(\frac{39}{9}\) = 4.33

then \(\frac{sum}{mean}\) = \(\frac{39}{4.33}\)

= 9