WAEC Mathematics Past Questions & Answers - Page 48

236.

In the diagram, PQ and PS are tangents to the circle O. If PSQ = m, <SPQ = n and <SQR = 33\(^o\), find the value of (m + n)

A.

103\(^o\)

B.

123\(^o\)

C.

133\(^o\)q

D.

143\(^o\)

Correct answer is B

< SQP = 180 - (90 + 33)  < on a ----

= 180 - (123)

= 57\(^o\)

Therefore, (m + n) = 123\(^o\)

237.

The diagram shows a circle O. If &lt; ZYW = 33\(^o\) , find &lt; ZWX

A.

33\(^o\)

B.

57\(^o\)

C.

90\(^o\)

D.

100\(^o\)

Correct answer is C

In ZY = 90\(^o\)  < subtends In a semi O

ZWY = 180 - (90\(^o\)  + 33)

= 57

ZWX = 57 + 33 = 90\(^o\) 

238.

In the diagram, XY is a straight line.

A.

60\(^o\)

B.

90\(^o\)

C.

100\(^o\)

D.

120\(^o\)

Correct answer is B

<POX = <POQ; <ROY = QOR

2 <POQ + 2 <ROY = 180

2(<POQ = <ROY) = 180

<POQ + <ROY = 90

239.

The diagram shows a circle centre O. if <STR = 29 and <RST = 45, calculate the value of <STO

A.

12\(^o\)

B.

15\(^o\)

C.

29\(^o\)

D.

34\(^o\)

Correct answer is A

SRT = 180 - (46 + 29) sum of < s in a

= 180 - 75

= 105

SOT = 2 x 46 < at the centre is twice all the circle = 92

RTO = 180 - (96 + 43)

= 41

STO = 41 - 29

= 12\(^o\)

240.

Fig. 1 and Fig. 2 are the addition and multiplication tables respectively in modulo 5. Use these tables to solve the equation (n \(\oplus 4\))

A.

1

B.

2

C.

3

D.

4

Correct answer is C

(n \(\oplus\) 4) \(\oplus\) 3 = 0 (mod 5)

(3 \(\oplus\) 4) \(\oplus\) 3

12 \(\oplus\) 3 = 15 (mod 5)

(5 x 3 + 0) = 0 (mod 5)