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.

1,916.

A cuboid has a diagonal of length 9cm and a square base of side 4cm. What is its height?

A.

9cm

B.

\(\sqrt{65}\)cm

C.

\(4\sqrt{2}\)cm

D.

7cm

E.

6.5cm

Correct answer is B

Given a cuboid, the diagonal cuts a face of the cuboid into 2 right-angled triangles.

Hence, using the Pythagoras theorem, we have

\(9^{2} = 4^{2} + x^{2}\)

\(81 = 16 + x^{2}\)

\(x^{2} = 81 - 16 = 65\)

\(\therefore x = \sqrt{65} cm\)

1,917.

Which of the following fractions is less than one-third?

A.

\(\frac{22}{63}\)

B.

\(\frac{4}{11}\)

C.

\(\frac{15}{46}\)

D.

\(\frac{33}{98}\)

E.

\(\frac{122}{303}\)

Correct answer is C

All others are greater than 0.333 when converted to their fractions except \(\frac{15}{46}\)

1,918.

A group of 14 children children received the following scores in a reading test: 35, 35, 26, 26, 26, 29, 29, 29, 12, 25, 25, 25, 25, 17. What was the median score?

A.

29

B.

26

C.

24

D.

25

E.

23

Correct answer is B

Arranging the scores in ascending order:

12, 17, 25, 25, 25, 25, 26, 26, 26, 29, 29, 29, 35, 35.

The median is the average of the 7th and 8th marks.

= \(\frac{26 + 26}{2} = 26\)

1,919.

Find the value of x satisfying \(\frac{x}{2}\) - \(\frac{1}{3}\) < \(\frac{2x}{5}\) + \(\frac{1}{6}\)

A.

x < 5

B.

x < 7\(\frac{1}{2}\)

C.

x > 5

D.

x > 7\(\frac{1}{2}\)

Correct answer is A

\(\frac{x}{2} - \frac{1}{3} < \frac{2x}{5} + \frac{1}{6}\)

\(\frac{x}{2} - \frac{2x}{5} < \frac{1}{6} + \frac{1}{3}\)

\(\frac{x}{10} < \frac{1}{2}\)

\(2x < 10 \implies x < 5\)

1,920.

Find a two-digit number such that three times the tens digit is 2 less than twice the units digit and twice the number is 20 greater than the number obtained by reversing the digits

A.

24

B.

42

C.

74

D.

47

E.

72

Correct answer is D

Let the tens digits of the number be x and the unit digit be y

3x = 2y - 2

3x - 2y = -2.......(i)

If the digits are interchanged, the tens digit becomes y, the unit digit becomes x. Hence 2(10x + y) = 10y + x + 20

(20x + 2y) - (10y + x) = 20

19x - 8y = 20.....(ii)

Multiply eqn.(i) by 8 and eqn.(ii) by 2

24x - 16y = -16......(iii)

38x - 16y = 40........(iv)

eqn(iv) - eqn(iii)

14x = 56

x = 4

Sub. for x = 4 in eqn(i)

3(4) - 2y = -2

14 = 2y

y = 7

So the original number is 10(4) + 7

i.e. 10x + y

= 47