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.

1,841.

Find the roots of the equation 10x2 - 13x - 3 = 0

A.

x = \(\frac{3}{5}\) or -\(\frac{1}{2}\)

B.

x = \(\frac{3}{10}\) or -1

C.

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

D.

x = \(\frac{1}{5}\) or \(\frac{-3}{2}\)

E.

x = -\(\frac{1}{5}\) or \(\frac{3}{2}\)

Correct answer is E

10x2 - 13x - 3 = 0 = 10x2 - 15x + 2x - 3 = 0

5x(2x - 3) + 2x - 3 = 0

= (5x + 1)(2x - 3) = 0

5x + 1 = 0 or 2x - 3 = 0

x = -\(\frac{1}{5}\) or \(\frac{3}{2}\)

1,842.

List all integer values of x satisfying the inequality -1 < 2x - 5 \(\leq\) 5

A.

<2, 3, 4, 5

B.

3, 4, 5

C.

2, 3, 4

D.

3, 4

Correct answer is B

\(-1 < 2x - 5 \leq 5\)

\(\implies -1 + 5 < 2x - 5 + 5 \leq 5 + 5\)

\(4 < 2x \leq 10\)

\(\implies 2 < x \leq 5 \)

= 3, 4, 5.

1,843.

The median of the set of numbers 4, 9, 4, 13, 7, 14, 10, 17 is

A.

13

B.

7

C.

\(\frac{19}{2}\)

D.

\(\frac{39}{4}\)

E.

10

Correct answer is C

Rearranging in increasing order 4, 4, 7, 9, 10, 13, 14, 17, the

median = \(\frac{(9 + 10)}{2}\)

= \(\frac{19}{2}\)

1,844.

When a dealer sells a bicycle for N81 he makes a profit of 80%. What did he pay for the bicycle?

A.

N73

B.

N74.52

C.

N75

D.

N87.48

E.

N75.52

Correct answer is C

Profit = 8%

\(\therefore S.P = N81 = (100 + 8)% = 108%\)

\(108% = N81\)

\(100% = \frac{81}{108} \times 100\)

= \(\frac{8100}{108} = N75\)

1,845.

Rationalize the denominator of the given expression \(\frac{\sqrt{1 + a} - \sqrt{a}}{1 + a + \sqrt{a}}\)

A.

1 + 2a - 2\(\sqrt{a(1 + a)}\)

B.

\(\sqrt{1(1 + a)}\)

C.

2a - 2\(\sqrt{a(1 + a)}\)

D.

1 + 2a - 2\(\sqrt{a + b}\)

Correct answer is A

\(\frac{\sqrt{1 + a} - \sqrt{a}}{1 + a + \sqrt{a}}\) = \(\frac{\sqrt{1 + a} - \sqrt{a}}{\sqrt{1 + a} + \sqrt{a}}\) x \(\frac{\sqrt{1 + a} - \sqrt{a}}{\sqrt{1 + a} - \sqrt{a}}\)

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

= 2a + a(1 + a)

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