WAEC Past Questions and Answers - Page 2670

13,346.

What sum of money will amount to D10,400 in 5 years at 6% simple interest?

A.

D8,000.00

B.

D10,000.00

C.

D12,000.00

D.

D16,000.00

Correct answer is A

A = P + 1

I = A - P

= 10,400 - P

Now using I = \(\frac{P \times T \times R}{100}\)

i.e. 10,400 - P = \(\frac{P \times 5 \times 6}{100}\)

= 100(10,400 - P) = 30P

10(10,400 - P) = 3P

104,000 - 10P = 3P

104,000 - 10P = 3P

104,000 = 3P + 10P

= 104,000 = 13P

P = \(\frac{104,000}{100}\)

P = D8,000

13,347.

Simplify; \(\frac{3^{n - 1} \times 27^{n + 1}}{81^{n}}\)

A.

32n

B.

9

C.

3n

D.

3n + 1

Correct answer is B

\(\frac{3^{n - 1} \times 27^{n + 1}}{81^{n}}\)

= \(\frac{3^{n - 1} \times 3^{3(n + 1)}}{3^{4n}}\)

= 3\(^{n - 1 + 3n + 3 - 4n}\)

= 3\(^{4n - 4n - 1 + 3}\)

= 32

= 9

13,348.

On a map, 1cm represent 5km. Find the area on the map that represents 100km2.

A.

2cm2

B.

4cm2

C.

8cm2

D.

8cm2

Correct answer is B

On a map, 1cm represents 5km. Then it follows that 1cm2 represents 25km2. Acm2 represents 100km2. By apparent cross-multiplication, 1cm2 x 100km2 = Acm2x 25km2

therefore A = \(\frac{100}{25}\) = 4cm2

13,349.

Which of following is a valid conclusion from the premise. "Nigeria footballers are good footballers"?

A.

Joseph plays football in Nigeria therefore he is a good footballer

B.

Joseph is a good footballer therefore he is a Nigerian footballer

C.

Joseph is a Nigerian footballer therefore he is a good footballer

D.

Joseph plays good football therefore he is a Nigerian footballer

Correct answer is C

From the venn diagram, Nigeria footballers from a subset of good footballers.

13,350.

The distance, d, through which a stone falls from rest varies directly as the square of the time, t, taken. If the stone falls 45cm in 3 seconds, how far will it fall in 6 seconds?

A.

90cm

B.

135cm

C.

180cm

D.

225cm

Correct answer is C

d \(\alpha\) t2

d = t2 k

where k is a constant. d = 45cm, when t = 3s; thus 45 = 32 x t

k = \(\frac{45}{9}\) = 5

thus equation connecting d and t is d = 5t2

when t = 6s, d = 5 x 62

= 5 x 36

= 180cm