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.

1,871.

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

A.

x = -1 or 3

B.

x = 1 or 3

C.

x = 1 or -5

D.

x = -1 or 5

E.

x = -1 or -3

Correct answer is C

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

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

\(\frac{2}{x^2 + 4x + 3}\) = \(\frac{1}{4}\)

= x2 + 4x + 3 = 8

x2 + 4x - 5 = 0

= (x - 1)(x + 5) = 0

x = 1 or -5

1,872.

Simplify \(\frac{\sqrt{2}}{\sqrt{3} - \sqrt{2}}\) - \(\frac{3 - 2}{\sqrt{3} + \sqrt{2}}\)

A.

2\(\sqrt{2} - \sqrt{3}\)

B.

3(\(\sqrt{6}\) - 1)

C.

\(\sqrt{6}\) - 3

D.

-\(\frac{1}{2}\)

E.

\(\frac{-\sqrt{3}}{\sqrt{2} - \sqrt{2}}\)

Correct answer is B

\(\frac{\sqrt{2}}{\sqrt{3} - \sqrt{2}}\) - \(\frac{3 - 2}{\sqrt{3} + \sqrt{2}}\)

\(\frac{\sqrt{2}}{\sqrt{3} - \sqrt{2}}\) = \(\frac{\sqrt{2}}{\sqrt{3}}\) - \(\frac{x}{\sqrt{2}}\)

\(\frac{\sqrt{3} + \sqrt{2}}{3 + \sqrt{2}}\) = \(\sqrt{6}\) + 2

\(\frac{\sqrt{3} - \sqrt{2}}{\sqrt{3} + \sqrt{2}}\) = \(\frac{\sqrt{3} - \sqrt{2}}{\sqrt{3} + \sqrt{2}}\) x \(\frac{\sqrt{3} - \sqrt{2}}{\sqrt{3} - \sqrt{2}}\)

= 5 - 2\(\sqrt{6}\)

\(\sqrt{6}\) + 2 - (5 - 2 \(\sqrt{6}\)) = \(\sqrt{6}\) + 2 - 5 + 2\(\sqrt{6}\)

= 3\(\sqrt{6}\) - 3

= 3(\(\sqrt{6}\) - 1)

1,873.

In one and a half hours, the minute hand of a clock rotates through an angle of

A.

90o

B.

180o

C.

640o

D.

450o

E.

540o

Correct answer is E

1 hr = 60 mins, 60 mins = 360°

30 mins = \(\frac{360^o}{1}\) × \(\frac{30}{60}\)

= 180°

90 mins = 360° + 180°

= 540°

1,874.

A micrometer is defined as one millionth of a millimeter. A length of 12,000 micrometres may be represented as

A.

0.00012m

B.

0.0000012m

C.

0.000012m

D.

0.00000012m

E.

0.000000012m

Correct answer is C

1 UM = 10-6mm = 10-9m
1.2 x 104 x 10-9m = 1.2 x 10-5m (0.000012)

1,875.

An isosceles triangle of sides 13cm, 13cm, 10cm is inscribed in a circle. What is the radius of the circle?

A.

7cm

B.

12cm

C.

8cm

D.

36cm

E.

69cm

Correct answer is A

In \(\Delta DAC, \stackrel\frown{DAC} = \theta\)

\(\sin \theta = \frac{5}{13}\)

\(\theta = 22.6°\)

\(< DOC = 22.6° \times 2 = 45.2°\)

\(\sin 45.2 = \frac{5}{r} \implies r = \frac{5}{\sin 45.2}\)

\(r = 7.046cm\)

= \(7\frac{1}{24} cm\)