Mathematics questions and answers

Mathematics Questions and Answers

How good are you with figures and formulas? Find out with these Mathematics past questions and answers. This Test is useful for both job aptitude test candidates and students preparing for JAMB, WAEC, NECO or Post UTME.

421.

Four boys and ten girls can cut a field first in 5 hours. If the boys work at \(\frac{5}{4}\) the rate at which the girls work, how many boys will be needed to cut the field in 3 hours? 

A.

180

B.

60

C.

25

D.

20

Correct answer is D

Let x rep. numbers of boys that can work at \(\frac{5}{4}\) the rate at

 which the 10 girls work 

For 1 hrs, x boys will work for \(\frac{\frac{1}{5} \times 10}{4}\) 

x = \(\frac{5}{4}\) x 10 

= 8 boys 

8 boys will do the work of ten girls at the same rate 

4 + 8 = 12 bous cut the field in 5 hrs for 3 hrs, 

\(\frac{12 \times 5}{3}\) boys will be needed = 20 boys.

422.

Reach each number to two significant figures and then evaluate \(\frac{0.02174 \times 1.2047}{0.023789}\) 

A.

0

B.

0.9

C.

1.1

D.

1.2

Correct answer is C

\(\frac{0.021741 \times 1.2047}{0.023789}\) = \(\frac{0.0255 \times 1.2}{0.024}\) (to 216) 

= \(\frac{0.0264}{0.024}\) = 1.1

423.

Find all real number x which satisfy the inequality \(\frac{1}{3}\) (x + 1) - 1 > \(\frac{1}{5}\)(x + 4) 

A.

x < 11

B.

x < -1

C.

x > 6

D.

x > 11

Correct answer is D

\(\frac{1}{3}\) (x + 1) - 1 > \(\frac{1}{5}\)(x + 4)  = \(\frac{x + 1}{3} - 1\) > \(\frac{x + 4}{5}\) 

\(\frac{x + 1}{3} - \frac{x + 4}{5} -1\) > 0 

= \(\frac{5x + 5 - 3x - 12}{15}\) 

2x - 7 > 15

2x > 22 = x > 11

424.

Find all median of the numbers 89, 141, 130, 161, 120, 131, 131, 100, 108 and 119 

A.

131

B.

125

C.

123

D.

120

Correct answer is B

Arrange in ascending order

89, 100, 108, 119, 120,130, 131, 131, 141, 161

Median = \(\frac{120 + 130}{2}\) = 125

425.

Factorise (4a + 3) \(^2\) - (3a - 2)\(^2\)

A.

(a + 1)(a + 5)

B.

(a - 5)(7a - 1)

C.

(a + 5)(7a + 1)

D.

a(7a + 1)

Correct answer is C

[(4a + 3) \(^2\) - (3a - 2)\(^2\) = a\(^2\) - b\(^2\) = (a + b) (a - b) 

= [(4a + 3) + (3a - 2)] [(4a + 3) - (3a - 2)]

= [4a + 3 + 3a - 2] [4a + 3 - 3a + 2]

= (7a + 1)(a + 5)

(a + 5) (7a + 1)