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.

2,681.

In how many ways can 3 seats be occupied if 5 people are willing to sit?

A.

60

B.

20

C.

5

D.

120

Correct answer is A

5 people can take 3 places in;

5P3 ways, = \(\frac{5!}{(5 - 3)!}\) = \(\frac{5!}{2!}\)

= \(\frac{5 \times 4 \times 3 \times 2!}{2!}\)

= 5 x 4 x 3

= 60 ways

2,682.

In how many ways can a student select 2 subjects from 5 subjects?

A.

\(\frac{5!}{3!}\)

B.

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

C.

\(\frac{5!}{2!3!}\)

D.

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

Correct answer is C

A student can select 2 subjects from 5 subjects in;

5C3 ways, i.e. = \(\frac{5!}{2!(5 - 2)!}\)

= \(\frac{5!}{2!3!}\)

2,684.

If the variance of 3+x, 6, 4, x and 7-x is 4 and the mean is 5, find the standard deviation

A.

\(\sqrt{3}\)

B.

2

C.

3

D.

\(\sqrt{2}\)

Correct answer is B

Let \(\delta^2\) and \(\delta\) denote the variance and standard deviation of the distribution respectively.

But \(\delta^2\) = 4 (given)

Hence \(\delta\) = \(\sqrt{4}\) = 2

2,685.

\(\begin{array}{c|c}Age & 20 & 25 & 30 & 35 & 40 & 45 \\
\hline \text{No. of people} & 3 & 5 & 1 & 1 & 2 & 3 \end{array}\)

Calculate the median age of the frequency distribution in the table above

A.

25

B.

30

C.

35

D.

20

Correct answer is A

N = \(\sum f\) = 15

Hence the median age is the \(\frac{N + 1}{2}\)th age, i.e.

\(\frac{15 + 1}{2}\)th = 8th

From the table, the age that falls on the 8th position when arranged in ascending order is 25years