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.

836.

The volume of a cone of height 3cm is 38\(\frac{1}{2}\)cm3. Find the radius of its base. [Take \(\pi = \frac{22}{7}\)]

A.

3.0cm

B.

3.5cm

C.

4.0cm

D.

4.5cm

Correct answer is B

Using V = \(\frac{3}{1} \pi r^2h\),

so, 38\(\frac{1}{2} = \frac{1}{3} \times \frac{22}{7} \times r^2 \times 3\)

\(\frac{77}{2} = \frac{22}{7} \times r^2\)

r2 = \(\frac{77 \times 7}{2 \times 22}\)

r2 = \(\frac{49}{4}\)

Hence, r = \(\sqrt{\frac{49}{4}}\)

= 3\(\frac{1}{2}\)

837.

Ada draws the graph of y = x2 - x - 2 and y = 2x - 1 on the same axes. Which of these equations is she solving?

A.

x2 - x - 3 = 0

B.

x2 - 3x - 1 = 0

C.

x2 - 3x - 3 = 0

D.

x2 + 3x - 1 = 0

Correct answer is B

Given; y = x2 - x - 2, y = 2x - 1

Using y = y, gives

x2 - x - 2 = 2x - 1

x2 - 3x - 2 + 1 = 0

therefore, x2 - 3x - 1 = 0

838.

Adding 42 to a given positive number gives the same result as squaring the number. Find the number

A.

14

B.

13

C.

7

D.

6

Correct answer is C

Let the given positive number be x

Then 4 + x = x2

0 = x2 - x - 42

or x2 - x - 42 = 0

x2 - 7x + 6x - 42 = 0

x(x - 7) + 6(x - 7) = 0

= (x + 6)(x - 7) = 0

x = -6 or x = 7

Hence, x = 7

839.

If m = 4, n = 9 and r = 16., evaluate \(\frac{m}{n}\) - 1\(\frac{7}{9}\) + \(\frac{n}{r}\)

A.

1\(\frac{5}{16}\)

B.

1\(\frac{1}{16}\)

C.

\(\frac{5}{16}\)

D.

- 1\(\frac{37}{48}\)

Correct answer is D

If m = 4, n = 9, r = 16,

then \(\frac{m}{n}\) - 1\(\frac{7}{9}\) + \(\frac{n}{r}\)

= \(\frac{4}{9}\) - \(\frac{16}{9}\) + \(\frac{9}{16}\)

= \(\frac{64 - 256 + 81}{144}\)

= \(\frac{-111}{144}\)

= - 1\(\frac{37}{48}\)

840.

Find the equation whose roots are \(\frac{3}{4}\) and -4

A.

4x2 - 13x + 12 = 0

B.

4x2 - 13x - 12 = 0

C.

4x2 + 13x - 12 = 0

D.

4x2 + 13x + 12 = 0

Correct answer is C

Let x = \(\frac{3}{4}\) or x = -4

i.e. 4x = 3 or x = -4

(4x - 3)(x + 4) = 0

therefore, 4x2 + 13x - 12 = 0