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.

2,271.

Simplify and express in standard form \(\frac{0.00275 \times 0.0064}{0.025 \times 0.08}\)

A.

8.8 x 10-1

B.

8.8 x 10-2

C.

8.8 x 10-3

D.

8.8 x 103

Correct answer is C

\(\frac{0.00275 \times 0.0064}{0.025 \times 0.08}\)

Removing the decimals = \(\frac{275 \times 64}{2500 \times 800}\)

= \(\frac{88}{10^4}\)

\(88 x 10^{-4} = 88 x 10^{1} x 10^{-4} = 8.8 x 10^{-3}\)

2,272.

Three children shared a basket of mangoes in such a way that the first child took \(\frac{1}{4}\) of the mangoes and the second \(\frac{3}{4}\) of the remainder. What fraction of the mangoes did the third child take?

A.

\(\frac{3}{16}\)

B.

\(\frac{7}{16}\)

C.

\(\frac{9}{16}\)

D.

\(\frac{13}{16}\)

Correct answer is A

You can use any whole numbers (eg. 1. 2. 3) to represent all the mangoes in the basket.

If the first child takes \(\frac{1}{4}\) it will remain 1 - \(\frac{1}{4}\) = \(\frac{3}{4}\)

Next, the second child takes \(\frac{3}{4}\) of the remainder

which is \(\frac{3}{4}\) i.e. find \(\frac{3}{4}\) of \(\frac{3}{4}\)

= \(\frac{3}{4}\) x \(\frac{3}{4}\)

= \(\frac{9}{16}\)

the fraction remaining now = \(\frac{3}{4}\) - \(\frac{9}{16}\)

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

= \(\frac{3}{16}\)

2,273.

At what rate would a sum of N100.00 deposited for 5 years raise an interest of N7.50?

A.

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

B.

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

C.

1.5%

D.

25%

Correct answer is C

Interest I = \(\frac{PRT}{100}\)

∴ R = \(\frac{100 \times 1}{100 \times 5}\)

= \(\frac{100 \times 7.50}{500 \times 5}\)

= \(\frac{750}{500}\)

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

= 1.5%

2,274.

Correct 241.34(3 x 10-\(^3\))\(^2\) to 4 significant figures

A.

0.0014

B.

0.001448

C.

0.0022

D.

0.002172

Correct answer is D

first work out the expression and then correct the answer to 4 s.f = 241.34..............(A)

(3 x 10-\(^3\))\(^2\)............(B)

= 3\(^2\)x\(^2\)

= \(\frac{1}{10^3}\) x \(\frac{1}{10^3}\)

(Note that x\(^2\) = \(\frac{1}{x^3}\))

= 24.34 x 3\(^2\) x \(\frac{1}{10^6}\)

= \(\frac{2172.06}{10^6}\)

= 0.00217206

= 0.002172(4 s.f)

2,275.

The H.C.F. of a2bx + ab2x and a2b - b2 is

A.

b

B.

a + b

C.

b(a \(\div\) b)

D.

abx(a2 - b2)

Correct answer is B

a2bx + ab2x; a2b - b2

abx(a + b); b(a2 - b2)

b(a + b)(a + b)

∴ H.C.F. = (a + b)