WAEC Past Questions and Answers - Page 4009

20,041.

Find the 9th term of the arithmetic progression 18, 12, 6, 0, -6 .........

A.

-54

B.

-30

C.

30

D.

42

E.

66

Correct answer is B

18, 12, 6, 0, -6, 12, -18, 24, -30
9th term = -30

20,042.

A boy measured the length and breath of a rectangular lawn as 59.6m and 40.3m respectively instead of 60m and 40m. What is the percentage error in his calculation of the perimeter of the lawn?

A.

10%

B.

1.4%

C.

7%

D.

0.2%

E.

0.1%

Correct answer is E

Length = 59.6m Breath = 40.3m Perimeter = (59.6m + 40.3m) x 2 = 99.9 x 2 = 199.8m Actual measurement Perimeter = (60 + 40) x 2 = 100 x 2 = 200m Error = 200m - 199.8m = 0.2 Error =0.2/200 x 100/1 = 0.1%

20,043.

Simplufy Log104 + Log1025

A.

1

B.

2

C.

3

D.

4

E.

5

Correct answer is B

Log104 + Log1025 = Log10(4 + 25)
= Log10100 = Log10102
= 2Log1010 = 2 x 1 = 2

20,044.

Simplify 56x\(^{-4}\) \(\div\) 14x\(^{-8}\)

A.

2x-12

B.

3x-3

C.

4x-4

D.

4x-3

E.

4x4

Correct answer is E

\(56x^{-4} \div 14x^{-8}\)

= \(4x^{- 4 - (-8)}\)

= \(4x^{4}\)

20,045.

Simplify: \((2\frac{1}{6} - 1\frac{2}{3}) \div 2\frac{2}{3}\).

A.

3/16

B.

7/16

C.

1 13/24

D.

2 11/24

E.

10 2/5

Correct answer is A

\((2\frac{1}{6} - 1\frac{2}{3}) \div 2\frac{2}{3}\)

= \((\frac{13}{6} - \frac{5}{3}) \div \frac{8}{3}\)

= \(\frac{3}{6} \times \frac{3}{8}\)

= \(\frac{3}{16}\)