WAEC Mathematics Past Questions & Answers - Page 141

701.

Find the value to which N3000.00 will amount in 5 years at 6% per annum simple interest

N3,900.00

N3,750.00

N3,600.00

N3,300

Correct answer is A

A = P + I

p + $\frac{PRT}{100}$

A = N3000 (1 + $\frac{6 \times 5}{100}$)

= N3000(1 + 0.3)

A = N3000 (1.3)

= N3,900.00

702.

Arrange the following numbers in descending orders of magnitude: 22_three, 34_five, 21_six

21_six, 22_three, 34_five,

21_six, 34_five, 22_three

22_three, 34_five, 21_six

34_five, 21_six, 22_three

View answer & explanation

Correct answer is D

22_three, 34_five, 21_six = (2 x 3)(2 x 3^o), (3 x 5¹) = (4 x 5⁰), (2 x 6¹) + (1 x 6⁰)

= (6 + 2), (15 + 4), (12 + 1) = 8_ten, 29_ten, 13_ten in descending order

29_ten, 13_ten, 8_ten = 34_five, 21_six, 22_three

703.

If log 2 = x, log 3 = y and log 7 = z, find, in terms of x, y and z, the value of log ($\frac{28}{3}$)

2x + y - z

2x + z - y

x + y - 2x

x + x - y

View answer & explanation

Correct answer is B

log ($\frac{28}{3}) = \log (\frac{7 \times 4}{3})$

= log 7 + log 4 - log 3

log 7 + log 22 - log 3 = log 7 + 2 - log 3

= z + 2x - y

= 2x + z - y

704.

In a particular year, the exchange rate of naira (N) varies directly with the Dollars{$}. If N1122 is equivalent to $8, find the Naira equivalent of $36

N8976

N5049

N140.25

N31.17

View answer & explanation

Correct answer is B

N1122 = $8; x = $36

x x $8 = N1122 x $36

$\frac{N1122 \times $36}{$8}$ = x

x = N5049

705.

Simplify: (3$\frac{1}{2} + 4\frac{1}{3}) \div (\frac{5}{6} - \frac{2}{3}$)

1$\frac{1}{4}$

8$\frac{1}{2}$

View answer & explanation

Correct answer is D

(3$\frac{1}{2} + 4\frac{1}{3}) \div (\frac{5}{6} - \frac{2}{3}$) = (7$\frac{3 + 2}{6}) \div \frac{(5 - 4)}{6}$

7$\frac{5}{6} \div \frac{1}{6} = \frac{47}{6} \times \frac{6}{1}$ = 47