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.

3,376.

The volume of a cone of height 9cm is 1848cm\(^3\). Find its radius. [Take π = 22/7]

A.

7cm

B.

14cm

C.

28cm

D.

98cm

E.

196cm

Correct answer is B

1/3 πr\(^2\) x 9 = 1848
3 x πr2 = 1848 r2 = 1848/3 x 7/22 r = 14

\(\text{Volume of a cone} = \frac{1}{3} \pi r^2 h\)

\(\frac{1}{3} \times \frac{22}{7} \times r^2 \times 9 = 1848\)

\(r^2 = \frac{1848 \times 7}{22 \times 3}\)

\(r^2 = 196 \therefore r = 14cm\)

3,377.

The curved surface area of a cylindrical tin is 704cm\(^2\). Calculate the height when the radius is 8cm. [Take π = 22/7]

A.

3.5cm

B.

7cm

C.

14cm

D.

28cm

E.

32cm

Correct answer is C

Curved surface area of a cylindrical tin = \(2\pi rh\)

\(\therefore 2\pi rh = 704cm^2\)

\(2 \times \frac{22}{7} \times 8 \times h = 704\)

\(h = \frac{704 \times 7}{2 \times 22 \times 8}\)

\(h = 14cm\)

3,378.

The angle of a sector of a circle of radius 8cm is 240°. This sector is bent to form a cone. Find the radius of the base of the cone.

A.

16/3cm

B.

15/3cm

C.

16/5cm

D.

8/3cm

E.

16/10cm

Correct answer is A

L = θ/360 x 2πR = 240/360 x 2 x 22/7 x 8/1 ... (1)

This must be equal to the circumference of the circle which is 2πr = 44R/7 .... (2)

equate (1) and (2)

r = 16/3 = 51/3

3,379.

Solve the equation \(\frac{m}{3} + \frac{1}{2} = \frac{3}{4} + \frac{m}{4}\)

A.

-3

B.

-2

C.

2

D.

3

E.

4

Correct answer is D

\(\frac{m}{3} + \frac{1}{2} = \frac{3}{4} + \frac{m}{4}\)

\(\frac{m}{3} - \frac{m}{4} = \frac{3}{4} - \frac{1}{2}\)

\(\frac{m}{12} = \frac{1}{4}\)

\(4m = 12 \implies m = 3\)

3,380.

What must be added to the expression x\(^2\) - 18x to make it a perfect square?

A.

3

B.

9

C.

36

D.

72

E.

81

Correct answer is E

x\(^2\) - 18x to be a perfect square.

\((\frac{b}{2})^2\) is added to ax\(^2\) + bx + c in order to make it a perfect square.

\(x^2 - 18x + (\frac{-18}{2})^2\)

= \(x^2 - 18x + 81\)