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.

816.

The area of a rhombus is 110 cm\(^2\). If the diagonals are 20 cm and (2x + 1) cm long, find the value of x.

A.

5.0

B.

4.0

C.

3.0

D.

2.5

Correct answer is A

Diagonal |AC| = (2x + 1)cm

In the diagram,area of \(\Delta\)ABC

is \(\frac{110}{2}\) = \(\frac{1}{2}\) x |AC| x |HB|

55 = \(\frac{1}{2}\) x (2x + 1) x 10

55 = (2x + 1)5

55 = 10x + 5

55 - 5 = 10x

50 = 10x

x = \(\frac{50}{10}\)

= 5.0

817.

Which of the following is used to determine the mode of a grouped data?

A.

Bar chart

B.

Frequency polygon

C.

Ogive

D.

Histogram

Correct answer is D

No explanation has been provided for this answer.

818.

Make K the subject of the relation T = \(\sqrt{\frac{TK - H}{K - H}}\)

A.

K = \(\frac{H(T^2 - 1)}{T^2 - T}\)

B.

K = \(\frac{HT}{(T - 1)^2}\)

C.

K = \(\frac{H(T^2 + 1)}{T}\)

D.

K = \(\frac{H(T - 1)}{T}\)

Correct answer is A

T = \(\sqrt{\frac{TK - H}{K - H}}\)

Taking the square of both sides, give

T2 = \(\frac{TK - H}{K - H}\)

T2(K - H) = TK - H

T2K - T2H = TK - H

T2K - TK = T2H - H

K(T2 - T) = H(T2 - 1)

K = \(\frac{H(T^2 - 1)}{T^2 - T}\)

819.

In the given diagram, \(\bar{QT}\) and \(\bar{PR}\) are straight lines, < ROS = (3n - 20), < SOT = n, < POL = m and < QOL is a right angle. Find the value of n.

A.

35o

B.

40o

C.

55o

D.

60o

Correct answer is A

In the diagram, QOR + 2m(vertically opposite angles)

So, m + 90° + 2m = 180°

(angles on str. line)

3m = 180° - 90°

3m = 90°

m = \(\frac{90^o}{3}\)

= 30°

substituting 30° for m in

2m + 4n = 200° gives

2 x 30° + 4n = 200°

60° + 4n = 200°

4n = 200° - 60°

= 140°

n = \(\frac{140°}{4}\)

= 35°

820.

If \(\frac{\sqrt{2} + \sqrt{3}}{\sqrt{3}}\) is simplified as m + n\(\sqrt{6}\), find the value of (m + n)

A.

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

B.

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

C.

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

D.

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

Correct answer is C

\(\frac{\sqrt{2} + \sqrt{3}}{\sqrt{3}}\) = \(\frac{\sqrt{2} + \sqrt{3}}{\sqrt{3}}\) x \(\frac{\sqrt{3}}{\sqrt{3}}\)

= \(\frac{\sqrt{2} \times \sqrt{3} + \sqrt{3} \times \sqrt{3}}{\sqrt{3} \times \sqrt{3}}\)

= \(\frac{\sqrt{6} + 3}{3}\)

= \(\frac{3 + \sqrt{6}}{3}\)

= Hence, (m + n) = 1 + \(\frac{1}{3}\)


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