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.

626.

Find the value of x for which \(\frac{x - 5}{x(x - 1)}\) is defined

A.

0 or 5

B.

-5 or 5

C.

-11 or 5

D.

0 or 1

Correct answer is A

The expression \(\frac{x - 5}{x(x - 1)}\) is defined whten

x(x - 5) = 0.38

either x = 0 or x - 5 = 0

Hence, x = 0 or x = 5

627.

The total surface area of a hemispher is 75\(\pi cm^2\). Find the radius.

A.

5.0 cm

B.

7.0 cm

C.

8.5 cm

D.

12.0 cm

Correct answer is A

Total surface area of hemisphere is

3\(\pi r^2\) = 75\(\pi cm^2\)

\(r^2\) = \(\frac{75 \pi}{3 \pi}\)

\(r^2\) = 25

r = \(\sqrt{25}\)

r = 5cm

628.

The table shows the distribution of goals scored by 25 teams in a football competition. Calculate the probability that a team selected at random scored at most 3 goals.

A.

\(\frac{3}{25}\)

B.

\(\frac{1}{5}\)

C.

\(\frac{6}{25}\)

D.

\(\frac{2}{5}\)

Correct answer is D

No. of teams that scored at most 3 goals = 3 + 1 + 6 = 10

Hence, probability that a team selected at random scored at most 3 goals

= \(\frac{10}{25}\) = \(\frac{2}{5}\)

629.

The table shows the distribution of goals scored by 25 teams in a football competition. Calculate the probability that a team selected at randon scored either 4 or 7 goals.

A.

\(\frac{9}{25}\)

B.

\(\frac{1}{5}\)

C.

\(\frac{6}{25}\)

D.

\(\frac{2}{5}\)

Correct answer is A

Prob. (team scored 4 goals) = Prob. (team scored 7 goals) = \(\frac{3}{25}\)

Hence, probability that a team selected at random scored either 4 or 7 goals;

= \(\frac{6}{25} + \frac{3}{25}\)

= \(\frac{9}{25}\)

630.

The mean of 1, 3, 5, 7 and x is 4. Find the value of x

A.

2

B.

4

C.

6

D.

8

Correct answer is B

Mean = \(\frac{\sum x}{n}\)

4 = \(\frac{1 + 3 + 5 + 7 + x}{5}\)

4 x 5 = 16 + x

20 - 16 = x

4 = x

x = 4