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.

541.

Find \(\frac{\mathrm d y}{\mathrm d x}\) if \(y = \cos x\).

A.

\(\sin x\)

B.

\(- \sin x\)

C.

\(\tan x\)

D.

\(- \tan x\)

Correct answer is B

If \(y = \cos x\)

\(\frac{\mathrm d y}{\mathrm d x}\) =—\(\sin x\)

542.

A man stands on a tree 150 cm high and sees a boat at an angle of depression of 74°. Find the distance of the boat from the base of the tree.

A.

52 cm

B.

43 cm

C.

40 cm

D.

15 cm

Correct answer is B

\(\tan 16 = \frac{x}{150}\)

\(x = 150 \tan 16\)

= \(43 cm\)

543.

A circular arc subtends angle 150° at the centre of a circle of radius 12cm. Calculate the area of the sector of the arc.

A.

30\(\pi\) cm\(^2\)

B.

60\(\pi\) cm\(^2\)

C.

120\(\pi\) cm\(^2\)

D.

150\(\pi\) cm\(^2\)

Correct answer is B

Area of sector = \(\frac{\theta}{360°} \times \pi r^{2}\)

= \(\frac{150}{360} \times \pi \times 12^{2}\)

= 60\(\pi\) cm\(^{2}\)

544.

If \(N = \begin{pmatrix} 3 & 5 & -4 \\ 6 & -3 & -5 \\ -2 & 2 & 1 \end{pmatrix}\), find \(|N|\).

A.

65

B.

23

C.

17

D.

91

Correct answer is C

\(\begin{vmatrix} 3 & 5 & -4 \\ 6 & -3 & -5 \\ -2 & 2 & 1 \end{vmatrix}\)

= \(3(-3 - (-10)) - 5(6 - 10) + (-4)(12 - 6)\)

= \(21 + 20 - 24\)

= 17

545.

If X, Y can take values from the set (1, 2, 3 ,4), find the probability that the product of X and Y is not greater than 6

A.

\(\frac{5}{8}\)

B.

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

C.

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

D.

\(\frac{3}{8}\)

Correct answer is A

x 1 2 3 4
1 1* 2* 3* 4*
2 2* 4* 6* 8
3 3* 6* 9 12
4 4* 8 12 16

The numbers that are not greater than 6 are either less than 6 or equal to 6.

P(picking a number not greater than 6) = \(\frac{10}{16}\)

= \(\frac{5}{8}\)