1989 - WAEC Mathematics Past Questions and Answers - page 5
41
In the diagram above, O is the center of the circle. If ∠POR = 114o, calculate ∠PQR
A
123o
B
118.5o
C
117o
D
114o
correct option: a
Reflex POR = 2PQR
Reflex PQR = 360o - 114o = 246o
PQR = 246/2 = 123o
Users' Answers & CommentsReflex PQR = 360o - 114o = 246o
PQR = 246/2 = 123o
42
The angle of depression of a point on the ground from the top of a building is 20.3o. If the foot of the building is 40m, calculate the height of the building, correct to one decimal place
A
37.5m
B
28.1m
C
27.8m
D
14.8m
correct option: d
Tan 69.7 = 40/h
Users' Answers & Commentsh =
40/tan 69.7 =
40/2.703 h = 14.79 = 14.8
43
Solve for x: (x2 + 2x + 1) = 25
A
-6, -4
B
6, -4
C
6, 4
D
-6, 4
correct option: d
x2 + 2x + 1 = 25
x2 + 6x - 4x -24= 0
x(x + 6) - 4(x + 6) = 0
(x - 4) - (x + 6) = 0
x = 4 or -6 = -6,4
Users' Answers & Commentsx2 + 6x - 4x -24= 0
x(x + 6) - 4(x + 6) = 0
(x - 4) - (x + 6) = 0
x = 4 or -6 = -6,4
44
Given that logp = 2 logx + 3logq, which of the following expresses p in terms of x and q?
A
p = 5xq
B
p = 6xq
C
p = x2 + q3
D
p = 2x + 3q
correct option: e
log p = 2log x + 3log q
log p = logx 2 + logq 3
logp = log x 2q 3
p = x 2q 3
Users' Answers & Commentslog p = logx 2 + logq 3
logp = log x 2q 3
p = x 2q 3
45
sinθ = 1/2 and cosθ = -√3/2, what is the value of θ?
A
30 0
B
60 0
C
90 o
D
120 o
correct option: e
Users' Answers & Comments46
What is the probability that 3 customers waiting in a bank will be served in the sequence of their arrival at the bank
A
1/6
B
1/3
C
1/2
D
2/3
correct option: a
Probability that 3 customers are attended to in the sequence they arrive
= prob of attending to the 1st arrival x prob of attending to the second last x prob of attending to the last
= \(\frac{1}{3} \times \frac{1}{2} \times \frac{1}{1}\)
= \(\frac{1}{6}\)
47
In the diagram, O is the center of the circle, If ∠POQ = 80o and ∠PRQ = 5x, find the value of x.
A
4o
B
8o
C
16o
D
20o
correct option: b
80o = 2 x 5x(angle at the center)
=80o = 10x; x = 80o/10
= 8o
Users' Answers & Comments=80o = 10x; x = 80o/10
= 8o
48
In an A.P the first term is 2, and the sum of the 1st and the 6th term is 161/2. What is the 4th term
A
12
B
91/2
C
8
D
7
correct option: b
1st term a = 2; 6th term = a + (16-1)d = 2 + 5d
2 + (2 + 5d) = 161/2; 4 + 5d = 161/2
5d = 12.5 ∴ = 2.5
the 4th term is 2 + (4-1)2.5= 91/2