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.

3,936.

Find the principal which amounts to N5,500 at a simple interest in 5 years at 2% per annum.

A.

N4,900

B.

N5,000

C.

N4,700

D.

N4,800

Correct answer is B

Principal, P = Amount, A - Interest, I.
A = P + I

I = (P.T.R)/100 = (P x 5 x 2)/100 = 10P/100 = P/10

But A = P + I,
=> 5500 = P + (P/10)
=> 55000 = 10P + P
=> 55000 = 11P

Thus P = 55000/11 = N5,000

3,937.

If \(x = \frac{y}{2}\),evaluate\(\left(\frac{x^{3}}{y^{3}}+\frac{1}{2}\right) \div \left(\frac{1}{2} - \frac{x^{2}}{y^{2}}\right)\)

A.

5/8

B.

5/2

C.

5/32

D.

5/16

Correct answer is B

\(x = \frac{y}{2} \)

\(\left(\frac{x^{3}}{y^{3}}+\frac{1}{2}\right) \div \left(\frac{1}{2} - \frac{x^{2}}{y^{2}}\right)\)

\(\frac{x^3}{y^3} + \frac{1}{2} = (\frac{y}{2})^{3} \div y^{3} + \frac{1}{2}\)

= \(\frac{y^{3}}{8} \times \frac{1}{y^3} + \frac{1}{2}\)

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

= \(\frac{5}{8}\)

\(\frac{1}{2} - \frac{x^2}{y^2} = \frac{1}{2} - (\frac{y}{2})^{2} \div y^2)\)

= \(\frac{1}{2} - \frac{y^2}{4} \times \frac{1}{y^2}\)

= \(\frac{1}{2} - \frac{1}{4}\)

= \(\frac{1}{4}\)

\(\therefore \left(\frac{x^{3}}{y^{3}}+\frac{1}{2}\right) \div \left(\frac{1}{2} - \frac{x^{2}}{y^{2}}\right) = \frac{5}{8} \div \frac{1}{4}\)

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

3,938.

A car dealer bought a second-hand car for N250,000 and spent N70,000 refurbishing it. He then sold the car for N400,000. What is the percentage gain?

A.

60%

B.

32%

C.

25%

D.

20%

Correct answer is C

Total cost = N(250,000 + 70,000) = N320,000
Selling price = N400,000 (given)
Gain = SP - CP = N(400,000 - 320,000) = N80,000
Gain % = gain/CP x 100 = (80,000/320,000) x 100

Gain % = 25%

3,939.

Given that \(p = 1 + \sqrt{2}\) and \(q = 1 - \sqrt{2}\), evaluate \(\frac{p^{2} - q^{2}}{2pq}\).

A.

2(2+√2)

B.

-2(2+√2)

C.

2√2

D.

-2√2

Correct answer is D

\(\frac{p^{2} - q^{2}}{2pq} = \frac{(p + q)(p - q)}{2pq}\)

= \(\frac{(1 + \sqrt{2} - (1 - \sqrt{2}))(1 + \sqrt{2} + 1 - \sqrt{2})}{2(1 + \sqrt{2})(1 - \sqrt{2})}\)

= \(\frac{(2\sqrt{2})(2)}{-2}\)

= \(-2\sqrt{2}\)

3,940.

Simplify \((\sqrt[3]{64a^{3}})^{-1}\)

A.

4a

B.

1/8a

C.

8a

D.

1/4a

Correct answer is D

\((\sqrt[3]{64a^{3}})^{-1} = (\sqrt[3]{(4a)^{3}})^{-1}\)

= \((4a)^{-1} \)

= \(\frac{1}{4a}\)