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.

3,541.

Find the product xy if, x, 3/2, 6/7, y are in G.P

A.

24/49

B.

4/7

C.

9/7

D.

7/4

E.

21/8

Correct answer is C

In GP, when you are given three consecutive terms, say f, g, h, then

\(f \times h = g^2\)

Given: \(x, \frac{3}{2}, \frac{6}{7}, y\), then

\(\frac{6x}{7} = (\frac{3}{2})^2 \implies \frac{6x}{7} = \frac{9}{4} ... (i)\)

Also, \(\frac{3y}{2} = (\frac{6}{7})^2 \implies \frac{3y}{2} = \frac{36}{49} ... (ii)\)

From \(\frac{6x}{7} = \frac{9}{4} \implies x = \frac{9 \times 7}{6 \times 4}\)

\(x = \frac{21}{8}\)

Also, \(\frac{3y}{2} = \frac{36}{49} \implies y = \frac{2 \times 36}{3 \times 49}\)

= \(\frac{24}{49}\)

\(xy = \frac{21}{8} \times \frac{24}{49} = \frac{9}{7}\)

3,542.

When an aeroplane is 800m above the ground, its angle of elevation from a point P on the ground is 30o. How far is the plane from P by line of sight?

A.

400m

B.

800m

C.

1500m

D.

1600m

E.

1700m

Correct answer is D

From the diagram, \(\sin 30 = \frac{800}{x}\)

\(x = \frac{800}{\sin 30} \)

= \(\frac{800}{0.5} \)

= 1600 m

3,543.

A student measured the length of a room and obtained the measurement of 3.99m. If the percentage error of is measurement was 5% and his own measurement was smaller than the length , what is the length of the room?

A.

3.78m

B.

3.80m

C.

4.18m

D.

4.20m

E.

4.788m

Correct answer is D

Let the actual length of the room = y m

\(\therefore \frac{y - 3.99}{y} \times 100% = 5%\)

\(100(y - 3.99) = 5y \implies 100y - 399 = 5y\)

\(100y - 5y = 399 \implies y = \frac{399}{95}\)

y = 4.2 m

3,544.

If log\(_{10}\) a = 4; what is a?

A.

0.4

B.

40

C.

400

D.

1000

E.

10000

Correct answer is E

log\(_{10}\) a = 4

a = 10\(^4\)

= 10000

3,545.

Simplify 0.63954 ÷ 0.003 giving your answer correct to two significant figures

A.

213.18

B.

213.00

C.

213

D.

210

E.

21

Correct answer is D

= \(\frac{0.63954}{0.003}\) 

moving the decimal places, we have

= \(\frac{639.54}{3}\)

= 213.18

\(\approxeq\) 210 (to 2 s.f.)