WAEC Mathematics Past Questions & Answers - Page 333

1,661.

In the diagram above, O is the centre of the circle through points L, M and N, if ∠MLN = 74o and ∠MNL = 39o, calculate ∠LON.

A.

67o

B.

100o

C.

113o

D.

126o

E.

134o

Correct answer is E

From the diagram, < LMN = 180° - (74° + 39°) (sum of angle in a triangle)

= 67°

< LON = 2 x 67° (angle subtended at the centre is twice the angle at the circumference)

= 134°

1,662.

A cone is made from a sector of circle of radius 14cm and angle of 90o. What is the area of the curved surface of the cone? (Take x = 22/7)

A.

22cm2

B.

38.5cm2

C.

77cm2

D.

154cm2

E.

308cm2

Correct answer is D

Length of arc =
θ/360
* 2πr


=> r =
90/360
*
14/4
= 3.5

slant height t = 14cm
curved surface area of cone = πrl
=> 3.142 x 3.5 x 14 = 153.95

1,663.

Which of the regions P, Q, R, S and T satisfies the following 0 < y < 1, y < x + 2, x < 0

A.

P

B.

Q

C.

R

D.

S

E.

T

Correct answer is E

No explanation has been provided for this answer.

1,665.

Factorize 5y2 + 2y - 3a2

A.

(5y - a) (y + 3a)

B.

(5y + a) (y - 3a)

C.

5y2 + a (2y - 3a)

D.

(y - a) (5y + 3a)

E.

(y + a) (5y - 3a)

Correct answer is E

5y 2 + 5ay - 3ay - 3a 2
5y(y + a) - 3a(y + a)
(y + a) (5y - 3a)