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.

131.

Given that log\(_3\) 27 = 2x + 1, find the value of x.

A.

0

B.

1

C.

2

D.

3

Correct answer is B

Recall that: log\(_3\) 27 → log\(_3\)3\(^3\)

3log\(_3\)3 → 3 * 1

= 3

Then log\(_3\) 27 = 2x + 1

→ 3 = 2x + 1 

3 - 1 = 2x

2 = 2x

1 = x

132.

A trader made a loss of 15% when an article was sold. Find the ratio of the selling price : cost price

A.

3:20

B.

3:17

C.

17:20

D.

20:23

Correct answer is C

Where the loss= (100-15)%

= 85%

Ratio = 85:100 or 17:20

133.

If the equations x\(^2\) - 5x + 6 = 0 and x + px + 6 = 0 have the same roots, find the value of p.

A.

5

B.

6

C.

-5

D.

-6

Correct answer is C

If "x" is the same for both equations, then they are equivalent.

 (i.e., the equations have same roots), then the equations are equivalent.

Then p = -5

134.

The straight line y = mx - 4 passes through the point(-4,16). Calculate the gradient of the line

A.

-5

B.

-3

C.

3

D.

5

Correct answer is A

where x=-4 and y = 16, 
16 = -4m - 4
4m = -16 - 4
4m = -20
M = -5

135.

The mean of two numbers x and y is 4. Find the mean of four numbers x, 2x, y and 2y

A.

2

B.

4

C.

6

D.

8

Correct answer is C

Since the mean of the two numbers x and y is:

\(\frac{x+y}{2}\) = 4

 x+y =2 * 4

x+y = 8

then we get:

\(\frac{x+2x+y+2y}{4}\)

=(\(\frac{3x+3y}{4}\))

= 3(\(\frac{x+y}{4}\)) → 3(\(\frac{8}{4}\)) 

= 3 * 2

= 6