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.

4,001.

If \(m*n = (\frac{m}{n} - \frac{n}{m}\)) for m, n belong to R, evaluate -3*4

 

A.

\(\frac{-25}{12}\)

B.

\(\frac{-7}{12}\)

C.

\(\frac{7}{12}\)

D.

\(\frac{25}{12}\)

Correct answer is C

\(m*n = \frac{m}{n}-\frac{n}{m}

= \frac{-3}{4} - \frac{4}{-3}

= \frac{-3}{4} + \frac{4}{3}

= \frac{(-9+16)}{12}

= \frac{7}{12}\)

4,002.

Simplify \(\sqrt{\frac{(0.0023 \times 750)}{(0.00345 \times 1.25)}}\)

A.

15

B.

20

C.

40

D.

75

Correct answer is B

Multiply appropriately to remove decimals on both numerator and denominators.

Such that you have \(\sqrt{\frac{(23000 \times 750)}{(345 \times 125)}}\)

Dividing, => \(\sqrt{400} = 20\).

4,003.

If 2\(_9\) x (Y3)\(_9\) = 3\(_5\) x (Y3)\(_5\), find the value of Y.

A.

4

B.

3

C.

2

D.

1

Correct answer is D

(2 x 9 \(^0\) ) (3 x 9 \(^1\)+ Y x 9\(^0\)) = (3 x 5 \(^0\))(3 x 5\(^1\) + Y x 5\(^0\)).

(2 * 1)(3 *9 + y) = (3 * 1)(3 * 5 + y)

2(27+y) = 3(15 + y)

54 + 2y= 45 + 3y

54 - 45 = 3y - 2y

y=9

4,004.

What is the answer when 2434\(_6\) is divided by 42\(_6\)?

A.

236

B.

356

C.

526

D.

556

Correct answer is B

Hint: Two methods can be used;

1. Direct division (if you know division in number bases)

2. Convert both sides to base 10, divide and convert your answer back to base 6. Your answer should be 356

2434\(_6\) to base 10

2 \(\times\) 6\(^3\) + 4 \(\times\) 6\(^2\) + 3 \(\times\) 6\(^1\) + 4 \(\times\) 6\(^0\)

2 \(\times\) 216 + 4 \(\times\) 36 + 3 \(\times\) 6 + 4 \(\times\) 1

432 + 144 + 18 + 4 = 598

And: 42\(_6\) to base 10

4 \(\times\) 6\(^1\) + 2 \(\times\) 6\(^0\)

4 \(\times\) 6 + 2 \(\times\) 1

24 + 2 = 26

Then divide 598 by 26 

= 23

Then convert 23\(_{10}\) to base 6

4,005.

A trader bought 100 oranges at 5 for N1.20, 20 oranges got spoilt and the remaining were sold at 4 for N1.50. Find the percentage gain or loss.

A.

30% gain

B.

25% gain

C.

30% loss

D.

25% loss

Correct answer is B

Cost price (cp) = (100/5) x N1.20 =N24.00
Selling price (sp) = 100-20 = 80
(80/4) x N1.50 = N30.00

Gain = SP-CP = N30.00-N24.00 = N6.00
Gain% = (gain/CP) x 100 = 25%