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.

2,961.

In a bag of oranges, the ratio of the good ones to the bad ones is 5:4. If the number of bad oranges in the bag is 36, how many oranges are there in the altogether?

A.

81

B.

72

C.

54

D.

45

Correct answer is A

Ratio of good ones to bad ones is 5:4; If 36 is bad;

∴ the good ones = \(\frac{5\times 36}{4}=45\) oranges. 

The total number of oranges is 36 + 45 = 81.

2,962.

If N varies directly as M and N = 8 when M = 20 find M when N = 7

A.

13

B.

15

C.

\(17\frac{1}{2}\)

D.

\(18\frac{1}{2}\)

Correct answer is C

N ∝ M
∴N = kM where k is a constant
N = 8 when M = 20
∴ 8 = k x 20
\(k = \frac{8}{20} = \frac{2}{5}\\
∴ N = \frac{2}{5}M\\
If N = 7\\
∴ 7 = \frac{2}{5}M\\
M = \frac{35}{2} = 17\frac{1}{2}\)

2,963.

In a class of 80 students, every students studies Economics or Geography or both. If 65 students study Economics and 50 study Geography, how many study both subjects?

A.

15

B.

30

C.

35

D.

45

Correct answer is C

Let c = no of students that offered both subjects ∴ No of students offering Economics = 65 - c No of students offering Geography = 50 - c 65 - c + c + 50 - c = 80 115 - c = 80 c = 35 35 students offer both Economics and Geography.

2,964.

Evaluate \(log_{10}5 + log_{10}20\)

A.

2

B.

3

C.

4

D.

5

Correct answer is A

\(log_{10}5 + log_{10}20\\
log_{10}[5\times 20]\\
log_{10}100\\
log_{10}10^2\\
2log_{10}10=2\)

2,965.

Evaluate \((20_{three})^2 - (11_{three})^2\) in base three

A.

101

B.

121

C.

202

D.

2020

Correct answer is C

\((20_{three})^2 - (11_{three})^2\)

= \((20_{3} - 11_{3})(20_{3} + 11_{3})\)

= \((2_{3})(101_{3})\)

= \(202_{3}\)