WAEC Mathematics Past Questions & Answers - Page 251

1,251.

O is the centre of the circle PQRS. PR and QS intersect at T POR is a diameter, ∠PQT = 42o and ∠QTR = 64o; Find ∠QRT

A.

68o

B.

64o

C.

42o

D.

32o

E.

22o.

Correct answer is A

TQR = 90 - 42 = 48o
QRT = 180 - (64 - 48)
    = 180 - 112
    = 68o

1,252.

Find the value of t for which \(\frac{64}{27} = (\frac{3}{4})^{t - 1}\)

A.

-4

B.

-2

C.

11/3

D.

2

E.

4

Correct answer is B

\(\frac{64}{27} = (\frac{3}{4})^{t-1}\)

\((\frac{3}{4})^t = \frac{64}{27} \times \frac{3}{4} = \frac{16}{9}\)

\((\frac{3}{4})^t = (\frac{9}{16})^{-1}\)

\((\frac{3}{4})^t = (\frac{3}{4})^{-2}\)

t = -2

1,253.

Find the common ratio in the GP: log 3, log 9, log 81 ..........

A.

1

B.

2

C.

3

D.

6

E.

9

Correct answer is B

r = log9/log3 = 2log3/log3 = 2

1,254.

The eleventh term of an AP, is 25 and its first term is -3. Find its common difference.

A.

19/10

B.

21/5

C.

23/11

D.

21/2

E.

24/5

Correct answer is E

a + 10d = 25
-3 + 10d = 25
d = 28/10 = 24/5

1,255.

Divide 3.6721 by 4

A.

0.9180

B.

1.4180

C.

1.1680

D.

1.9180

Correct answer is A

\(\frac{3.6721}{4} = 0.918025\)

\(\approxeq\) 0.9180