WAEC Past Questions and Answers - Page 2273

11,361.

The lengths of the parallel sides of a trapezium are 9cm and 12cm. If the area of the trapezium is 105cm\(^2\), find the perpendicular distance between the parallel sides.

A.

5cm

B.

7cm

C.

10cm

D.

15cm

Correct answer is C

Area of a trapezium = \(\frac{[a+b]h}{2}\) 

105 = \(\frac{[9+12]h}{2}\) → 105 x 2 =21h

h = \(\frac{210}{21}\) → 10cm

11,362.

Find the correct to two decimal places, the volume of a sphere whose radius is 3cm. [Take π = \(\frac{22}{7}\)]

A.

72.57cm\(^3\)

B.

88.12cm\(^3\)

C.

10529cm\(^3\)

D.

113.14cm\(^3\)

Correct answer is D

Volume of sphere =  \(\frac{4πr^3}{3}\) →   \(\frac{4 x 22  x 3^3}{3}\)

=  \(\frac{792}{7}\)

= 113.14cm\(^3\)

11,363.

The age (years) of some members in a singing group are: 12, 47, 49, 15, 43, 41, 13, 39, 43, 41 and 36.

Find the mean

A.

33.35

B.

35.54

C.

34.45

D.

36.44

Correct answer is C

\(\frac{12 + 47 + 49 + 15 + 43 + 41 + 13 + 39 + 43 + 41 + 36}{11}\)

= \(\frac{379}{11}\)

= 34.45

11,364.

The age (years) of some members in a singing group are: 12, 47, 49, 15, 43, 41, 13, 39, 43, 41 and 36.

Find the lower quartile

A.

12

B.

13

C.

15

D.

20

Correct answer is C

Rearranged: 12,13,15, 36, 39, 41, 41, 43, 43, 47 and 49

Lower quartile or First quartile = \(\frac{total number of items}{4}\)

If odd: items numbers + 1 → \(\frac{11 items + 1}{4}\)

= \(\frac{12}{4}\)

Lower quartile = 3rd iems →15

11,365.

Solve \(\frac{y+2}{4}\) - \(\frac{y-1}{3}\) > 1

A.

y < -10

B.

y < -2

C.

y < 2

D.

y < 10

Correct answer is B

multiply both sides by the LCM

12 x \(\frac{y+2}{4}\) -  12 x \(\frac{y-1}{3}\) >12 x 1

3[y+2] - 4[y-1] > 12

3y + 6 - 4y + 4 > 12

-y + 2 > 12

-y > 12 - 10 = 2

y < -2