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.

481.

If \(P = (\frac{Q(R - T)}{15})^{\frac{1}{3}}\), make T the subject of the formula.

A.

\(T = \frac{15R - Q}{P^3}\)

B.

\(T = R - \frac{15P^3}{Q}\)

C.

\(T = \frac{R - 15P^3}{Q}\)

D.

\(T = \frac{R + P^3}{15Q}\)

Correct answer is B

\(P = (\frac{Q(R - T)}{15})^{\frac{1}{3}}\)

\(P^3 = \frac{Q(R - T)}{15}\)

\(Q(R - T) = 15P^3\)

\(R - T = \frac{15P^3}{Q}\)

\(T = R - \frac{15P^3}{Q}\)

482.

Points X and Y are 20km North and 9km East of point O, respectively. What is the bearing of Y from X? Correct to the nearest degree.

A.

24°

B.

56°

C.

127°

D.

156°

Correct answer is D

\(\tan \theta = \frac{9}{20} = 0.45\)

\(\theta = \tan^{-1} (0.45) \)

= 24.23°

\(\therefore\) The bearing of Y from X = 180° - 24.23°

= 155.77°

= 156° (to the nearest degree)

483.

Find the value of x and y in the simultaneous equation: 3x + y = 21; xy = 30

A.

x = 3 or 7, y = 12 or 8

B.

x = 6 or 1, y = 11 or 5

C.

x = 2 or 5, y = 15 or 6

D.

x = 1 or 5, y = 10 or 7

Correct answer is C

3x + y = 21 ... (i);

xy = 30 ... (ii)

From (ii), \(y = \frac{30}{x}\). Putting the value of y in (i), we have

3x + \(\frac{30}{x}\) = 21

\(\implies\) 3x\(^2\) + 30 = 21x

3x\(^2\) - 21x + 30 = 0

3x\(^2\) - 15x - 6x + 30 = 0

3x(x - 5) - 6(x - 5) = 0

(3x - 6)(x - 5) = 0

3x - 6 = 0 \(\implies\) x = 2.

x - 5 = 0 \(\implies\) x = 5.

If x = 2, y = \(\frac{30}{2}\) = 15;

If x = 5, y = \(\frac{30}{5}\) = 6.

484.

Simplify \(\frac{0.0839 \times 6.381}{5.44}\) to 2 significant figures.

A.

0.2809

B.

2.51

C.

3.5

D.

0.098

Correct answer is D

No explanation has been provided for this answer.

485.

If 2\(^{x + y}\) = 16 and 4\(^{x - y} = \frac{1}{32}\), find the values of x and y.

A.

x = \(\frac{3}{4}\), y = \(\frac{11}{4}\)

B.

x = \(\frac{3}{4}\), y = \(\frac{13}{4}\)

C.

x = \(\frac{2}{3}\), y = \(\frac{4}{5}\)

D.

x = \(\frac{2}{3}\), y = \(\frac{13}{4}\)

Correct answer is B

2\(^{x + y}\) = 16 ; 4\(^{x - y}\) = \(\frac{1}{32}\).

\(\implies 2^{x + y} = 2^4\)

\(x + y = 4 ... (1)\)

\(2^{2(x - y)} = 2^{-5} \)

\(2^{2x - 2y} = 2^{-5}\)

\(\implies 2x - 2y = -5 ... (2)\)

Solving the equations (1) and (2) simultaneously, we have

x = \(\frac{3}{4}\) and y = \(\frac{13}{4}\)