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.

2,776.

Evaluate, correct to the nearest whole number \(7\frac{1}{2}-\left(2\frac{1}{2}+3\right)\div\frac{33}{2}\)

A.

33

B.

8

C.

7

D.

0

Correct answer is C

\(7\frac{1}{2}-\left(2\frac{1}{2}+3\right)\div\frac{33}{2}\\
=\frac{15}{2}-\left(\frac{5}{2}+\frac{3}{1}\right)\times\frac{2}{33}\\
=\frac{15}{2}-\left(\frac{5+6}{2}\right)\times \frac{2}{33}=\frac{15}{2}-\frac{11}{2}\times \frac{2}{33}=\frac{15}{2}-\frac{1}{3}\\
=\frac{45-2}{6}=\frac{43}{6}\)

2,777.

Simplify \(\frac{5}{\sqrt{3}}-\frac{3}{\sqrt{2}}\)

A.

\(\frac{1}{6}(5\sqrt{3}-3\sqrt{2}\)

B.

\(\frac{1}{6}(15\sqrt{3}-6\sqrt{2}\)

C.

\(\frac{1}{6}(3\sqrt{2}-\sqrt{3}\)

D.

\(\frac{1}{6}(10\sqrt{3}-9\sqrt{2}\)

Correct answer is D

\(\frac{5}{\sqrt{3}}-\frac{3}{\sqrt{2}}=\frac{5\sqrt{2}-3\sqrt{3}}{\sqrt{6}}\\
=\frac{5\sqrt{2}-3\sqrt{3}}{\sqrt{6}} \times \frac{\sqrt{6}}{\sqrt{6}}Rationalize\\
\frac{\sqrt{6}(5\sqrt{2}-3\sqrt{3})}{6}\\
\frac{5\sqrt{12}-3\sqrt{18}}{6}=\frac{10\sqrt{3}-9\sqrt{2}}{6}\\
\frac{1}{6}(10\sqrt{3}-9\sqrt{2})\)

2,778.

Correct 0.04945 to two significant figures

A.

0.040

B.

0.049

C.

0.050

D.

0.49

Correct answer is B

0.04945 \(\approxeq\) 0.049. (to 2 sig. figs)

2,779.

A point on the ground is 5m away from the foot of a vertical wall 7 m high, Calculate, correct to the nearest degree, the angle of depression of the point from the top of the wall

A.

36o

B.

44o

C.

46o

D.

54o

Correct answer is D

θ= angle of depression of the point from the top of the wall
\(tan\theta = \frac{7}{5}=1.4; \theta = tan^{-1}(1.400)\
\theta = 54.4^{\circ}; \theta = 54^{\circ}\) to the nearest degree

2,780.

A bag contains 3 red and 2 white identical balls. lf 2 balls are picked at random from the bag, one after the other and with replacement, find the probability that they are of different colours

A.

\(\frac{36}{625}\)

B.

\(\frac{16}{625}\)

C.

\(\frac{12}{25}\)

D.

\(\frac{13}{25}\)

Correct answer is C

Prob(RW or WR) = Prob(RW) + Prob(WR)
\(Prob(R) = \frac{3}{5}:Prob(W) = \frac{2}{5}\\
Prob(RW\hspace{1mm}or\hspace{1mm}WR)=\frac{3}{5}\times\frac{2}{5}+\frac{2}{5}\times \frac{3}{5}\\
\frac{6}{25}+\frac{6}{25}=\frac{12}{25}\)