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.

2,396.

simplify \(\frac{1}{√3 - 2}\) - \(\frac{1}{√3 + 2}\)

A.

3

B.

\(\frac{2}{3}\)

C.

7

D.

-4

Correct answer is D

\(\frac{1}{√3 - 2}\) - \(\frac{1}{√3 + 2}\)

L.C.M = (3- 2) (3 + 2)

∴ \(\frac{1}{\sqrt{3 - 2}}\) - \(\frac{1}{\sqrt{3 - 2}}\) = \(\frac{\sqrt{3 + 2} - \sqrt{3 - 2}}{\sqrt{3 - 2} + \sqrt{3 - 2}}\)


\(\frac{√3 + 2 - √3 + 2}{3 - 2√3 + 2√3 - 4}\) = \(\frac{4}{3 - 2}\)

= \(\frac{4}{-1}\)

= -4

2,397.

Solve for y in the equation 10^1 x 5(2y - 2) x 4(y - 1) = 1

A.

\(\frac{3}{4}\)

B.

\(\frac{5}{4}\)

C.

\(\frac{2}{3}\)

D.

5

Correct answer is C

10y x 5(2y - 2) x 4(y - 1) = 1

but 10y - (5 x 2)y = 5y x 2y

= (Law of indices)

5y x 2y x 5(2y - 2) x 4(y - 1) = 1

but 4(y - 1) = 22(y - 1)

= 2y - 2 (Law of indices)

5y x 5(2y -2) x 2(- 2) = 1

5(3y -2) x 2y x 2(2y -2) = 1

= 5(3y -2) x 2(3y -2) = 1

But ao = 1

10(3y -2) = 10o

3y - 2 = 0

∴ y = \(\frac{2}{3}\)

2,398.

If 9\(^{(x - \frac{1}{2})} = 3^{x2}\)

Find x

A.

\(\frac{1}{2}\)

B.

1

C.

2

D.

3

Correct answer is B

9(x - \(\frac{1}{2}\)) 3x2 = 32(x - \(\frac{1}{2}\)) = 3x2
∴ 2(x - \(\frac{1}{2}\)) = x2

2x - 1 = x2

hence x2 - 2x + 1 = 0

(x - 1)(x - 1) = 0

x = 1

2,399.

Evaluate \(\frac{3524}{0.05}\) correct to 3 significant figures

A.

705

B.

70,000

C.

70,480

D.

70,500

Correct answer is D

\(\frac{3524}{0.05}\) = 70480

\(\approx\) 70500(3 s.g)

2,400.

Change 7110 to base 8

A.

1078

B.

1068

C.

718

D.

178

Correct answer is A

\(\begin{array}{c|c} 8 & 71 \\ 8 & 8 \text{rem} 7\\ 8 & 1 \text{rem} 0\end{array}\)

= 1078