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.

821.

Tom will be 25 years old in n years' time. If he is 5 years younger than Bade's present age.

A.

(30 - n)years

B.

(20 - n)years

C.

(25 - n)years

D.

(30 + n)years

Correct answer is A

Let Tom's present agr be x.

Then x = 25 - n

If Tom is 5 years younger than Bade, then Bade's present age is x + 5 = 25 - n + 5

= (30 - n)

822.

In the diagram, VW//YZ, |WX| = 6cm, |XY| = 16cm, |YZ| = 20cm and |ZX| = 12cm. Calculate |VX|

A.

3cm

B.

4cm

C.

6cm

D.

8cm

Correct answer is D

In the diagram, \(\frac{16}{12} = \frac{VX}{6}\) (similar \(\Delta\)s)

VX = \(\frac{16 \times 6}{12}\)

= 8cm

823.

The probability that kebba, Ebou and Omar will hit a target are \(\frac{2}{3}\), \(\frac{3}{4}\) and \(\frac{4}{5}\) respectively. Find the probability that only Kebba will hit the target.

A.

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

B.

\(\frac{7}{60}\)

C.

\(\frac{1}{30}\)

D.

\(\frac{1}{60}\)

Correct answer is C

Hence the probability that only Kebba will hit the target

= P(K)xP(E')xP(O')

= \(\frac{2}{3} \times \frac{1}{4} \times \frac{1}{5}\)

= \(\frac{1}{30}\)

824.

\(\begin{array}{c|c}
Scores & 0 - 4 & 5 - 9 & 10 - 14\\
\hline Frequency & 2 & 1 & 2\end{array}\)

The table shows the distribution of the scores of some students in a test. Calculate the mean scores.

A.

5.6

B.

6.2

C.

6.6

D.

7.0

Correct answer is D

To calculate the mean of grouped data,

- First step  to determine the midpoint (x) of each interval or class.

0 - 4 ►2

5 - 9  ► 7

 10 - 14  ►12

These midpoints must then be multiplied by the frequencies of the corresponding classes:

2 X 2 = 4 

1 X 7 = 7

2 X 12 = 24

Mean = ( 24 + 7 + 4) ÷ ( 2 + 1 + 2 )

: Mean = 7

825.

The scores of twenty students in a test are as follows: 44, 47, 48, 49, 50, 51, 52, 53, 53, 54, 58, 59, 60, 61, 63, 65, 67, 70, 73, 75. Find the third quartile.

A.

62

B.

63

C.

64

D.

65

Correct answer is C

Third quartile Q3 = \(\frac{3}{4}\)Nth

Alternatively:
Split the score into equal quarters

44, 47, 48, 49, 50,        51, 52, 53, 53, 54,         58, 59, 60, 61, 63,     65, 67, 70, 73, 75.

Third quartile Q3 = [63 + 65] / 2 = 64