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.

1,491.

The table shows the ages(in years) of twenty children chosen at random from a community. What is the median of the distribution? \(\begin{array}{c|c} Age(years) & 1 & 2 & 3 & 4 & 5 \\ \hline {\text {Number of children}} & 2 & 3 & 5 & 6 & 4 \end{array}\)

A.

3.5 years

B.

3.0 years

C.

2.5 years

D.

2.0 years

Correct answer is A

Median = (\(\frac{n + 1}{2})^{th}\)

= \(\frac{20 + 1}{2} = \frac{21}{2}\)

= 10.5

= \(\frac{{\text{10th term and 11th term}}}{2}\)

= \(\frac{3 + 4}{2} = \frac{7}{2}\)

= 3.5yrs

1,492.

The table shows the ages(in years) of twenty children chosen at random from a community. What is the mean age? \(\begin{array}{c|c} Age(years) & 1 & 2 & 3 & 4 & 5 \\ \hline {\text {Number of children}} & 2 & 3 & 5 & 6 & 4 \end{array}\)

A.

4.46 years

B.

3.35 years

C.

3.30years

D.

3.00 years

Correct answer is B

Mean(age) = \(\frac{(1 \times 2) + (2 \times 3) + (3 \times 5) + (4 \times 6) + (5 \times 4)}{2 + 3 + 5 + 6 + 4}\)

= \(\frac{2 + 6 + 15 + 24 + 20}{20}\)

= \(\frac{67}{20}\)

= 3.35yrs

1,493.

If the probability of an event occurring is x, what is the probability of the event not occurring?

A.

1 - x

B.

x - 1

C.

0

D.

\(\frac{1}{x}\)

Correct answer is A

If p is the probability of an event happening(occurring) and the probability of an event not occurring is p1 then p + p1 = 1

p1 = 1 - p

x1 = 1 - x