WAEC Mathematics Past Questions & Answers - Page 239

1,191.

The side of a rhombus is 10cm long, correct to the nearest whole number. Between what limits should the perimeter P lie?

A.

39cm ≤ P ≤41cm

B.

38cm ≤ P < 42cm

C.

38.5 ≤ P ≤ 41.5cm

D.

38.5 ≤ P ≤ 40cm

Correct answer is B

If the side = 10 cm, correct to the nearest whole number, then

The side ranges from 9.5 cm to 10.5 cm. (9.5 \(\leq\) s < 10.5)

Perimeter of a rhombus = 4 x side

\(\therefore\) 4 x 9.5 \(\leq\) perimeter < 4 x 10.5

= 38 cm \(\leq\) P < 42 cm

1,192.

Arrange in ascending order of magnitude \(26_8, 36_7, and 25_9\)

A.

\(25_9 26_8 36_7\)

B.

\(26_8 25_9 36_7\)

C.

\(36_7 26_8 25_9\)

D.

\(36_7 25_9 26_8\)

Correct answer is B

No explanation has been provided for this answer.

1,193.

The side of a square is increased from 20cm to 21cm. Calculate the percentage increase in its area

A.

2.5%

B.

9.3%

C.

10.0%

D.

10.25%

Correct answer is D

old area = 202 = 400
new area = 212 = 441
% increase in area \(=\frac{41}{400}\times \frac{100}{1}\\
=10.25\%\)

1,194.

A trader makes a loss of 15% when selling an article. Find the ratio, selling price : cost price

A.

3:20

B.

3:17

C.

17:20

D.

20:23

Correct answer is C

No explanation has been provided for this answer.

1,195.

Evaluate \(3.0\times 10^1 - 2.8\times 10^{-1}\)leaving the answer in standard form

A.

\(2\times 10^{-1}\)

B.

\(2\times 10^{2}\)

C.

\(2.972 \times 10^{1}\)

D.

\(2.972 \times 10^{2}\)

Correct answer is C

No explanation has been provided for this answer.