WAEC Mathematics Past Questions & Answers - Page 292

1,456.

Simplify \(\frac{2.25}{0.015}\) leaving your answer in standard form

A.

1.5 x 10-4

B.

1.5 x 10-2

C.

1.5 x 10-3

D.

1.5 x 101

E.

1.5 x 102

Correct answer is E

\(\frac{2.25}{0.015}\)

= \(\frac{2250}{15}\)

= \(150\)

= \(1.5 \times 10^{2}\)

1,457.

In the diagram above, QRS is a straight line, QP//RT, PRQ = 56°, ∠QPR =84° and ∠TRS = x°. Find x

A.

28°

B.

40°

C.

44°

D.

84°

E.

124°

Correct answer is B

< PQR = 180° - (84° + 56°)

= 40°

\(\therefore\) x = 40° (corresponding angles QP// RT)

1,458.

Two chords PQ and RS of a circle when produced meet at K. If ∠KPS = 31o and ∠PKR = 42o, find ∠KQR

A.

11o

B.

73o

C.

107o

D.

138o

E.

149o

Correct answer is C

No explanation has been provided for this answer.

1,459.

In the diagram above, |PQ| = |QR|, |PS| = |RS|, ∠PSR = 30o and ∠PQR = 80o. Find ∠SPQ.

A.

15o

B.

25o

C.

40o

D.

50o

E.

55o

Correct answer is B

Join PR
QRP = QPR
= 180 - 80 = 100/20 = 50o
SRP = SPR
= 180 - 30 = 150/2 = 75o
∴ SPQ = SPR - QPR
= 75 - 50 = 25o

1,460.

In the diagram above, |QR| = 12cm and |QS| = 10cm. If ∠PQR = 90°, ∠RSQ = 90° and PSQ is a straight line, find |PS|

A.

3.3cm

B.

4.4cm

C.

5cm

D.

5.5cm

E.

6.6cm

Correct answer is B

\(\frac{PQ}{RQ} = \frac{RQ}{SQ}\) (Similar triangles)

\(\therefore \frac{PS + 10}{12} = \frac{12}{10}\)

\(10 (PS + 10) = 12 \times 12\)

\(10 PS + 100 = 144 \implies 10 PS = 44\)

\(PS = 4.4 cm\)