Processing math: 100%

WAEC Mathematics Past Questions & Answers - Page 119

591.

Factorize the expression: am + bn - an - bm

(a - b)(m + n)

(a - b)(m - n)

(a + b)(m - n)

(a + b)(m + n)

View answer & explanation

Correct answer is B

am + bn - an - bm am - an - bm + bn a(m - n) - b(m - n) (a - b)(m - n)

592.

The height of a cylinder is equal to its radius. If the volume is 0.216 $\pi$ m $^3$ . Calculate the radius.

0.46m

0.60m

0.87m

1.80m

View answer & explanation

Correct answer is B

volume of cylinder = $\pi r^2$ h

0.216 $\pi$ m $^3$ = $\pi \times r^2 \times h$

Since r = h,

0.216 = r $^3$

r $^3$ = 0.216

r = $\sqrt[3]{0.216}$

= 0.6

593.

What is the value of 3 in the number 42.7531?

$\frac{3}{10000}$

$\frac{3}{1000}$

$\frac{3}{100}$

$\frac{1}{10}$

View answer & explanation

Correct answer is B

No explanation has been provided for this answer.

594.

The length of a piece of stick is 1.75m. A girl measured it as 1.80m. Find the percentage error

$\frac{28}{7}$ %

$\frac{29}{7}$ %

$\frac{20}{7}$ %

View answer & explanation

Correct answer is D

Error = 1.80m - 1.75m = 0.05m

%error = $\frac{\text{error}}{\text{true measurement}}$ x 100%

595.

The perimeter of a sector of a circle of radius 4cm is ( $\pi + 8$ )cm. Calculate the anle of the sector

45^o

60^o

75^o

90^o

View answer & explanation

Correct answer is A

Perimeter of sector = 2r + $\frac{\theta}{360^o} \times 2\pi r$

$\pi + 8 = 2 \times 4 + \frac{\theta}{3360^o} \times 2 \pi \times 4$

$\pi + 8 + \frac{\theta}{360^o} \times 8 \pi$

P + 8 - 8 = $\frac{\theta \pi}{456o}$

$\pi = \frac{\theta \pi}{45^o}$

$\theta \pi = 45^o$