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.

3,146.

Solve the equations: 4x -y = 11; 5x + 2y = 4.

A.

x = 6, y = 13

B.

x = -2, y = -3

C.

x = -2, y = 3

D.

x = 2, y = -3

E.

x = 2, y = 3.

Correct answer is D

4x - y = 11....(1) x 2     8x - 2y = 22....(3)

5x + 12y = 4....(2) x 1     5x + 2y = 4....(4)

add eqn (3) and (4)

13x = 26

x = 2

4(2) - y = 11 ⟹⟹ y = 8 - 11

y = -3.

3,147.

Which of the following equations has its roots as 4 and -5?

A.

x2 + 4x - 20 = 0

B.

x2 + x + 20 = 0

C.

x2 - x + 20 = 0

D.

x2 + x - 20 = 0

E.

x2 - x - 20 = 0

Correct answer is D

(x - 4)(x + 5) = 0
x\(^2\) + 5x - 4x - 20 = 0
x\(^2\) + x - 20 = 0

3,148.

Solve me equation: 2/3 (x + 5) = 1/4(5x - 3)

A.

11/7

B.

18/23

C.

3

D.

43/7

E.

7

Correct answer is E

2/3 (x + 5) = 1/4(5x - 3)
8x + 40 = 15x - 9
-7x = -49
x = 7

3,149.

Simplify log39 + log315 - log35

A.

log319

B.

log3

C.

3

D.

1

Correct answer is C

log3
(9 x 15)/5
= log327 = 3

3,150.

A student found the approximate value of 0.02548 correct to two places of decimal instead of two significant figures. Find the percentage error.

A.

0%

B.

131/3%

C.

15 5/13%

D.

2/3%

E.

20%

Correct answer is E

0.02548 \(\approxeq\) 0.03 (to 2 decimal places)

0.02548 \(\approxeq\) 0.025 (2 sig. figs)

Error = 0.03 - 0.025

= 0.005

% error = \(\frac{0.005}{0.025} \times 100%\)

= 20%