JAMB Mathematics Past Questions & Answers - Page 285

1,421.

Four members of a school first eleven cricket team are also members of the first fourteen rugby team. How many boys play for at least one of the two teams?

A.

25

B.

21

C.

16

D.

3

Correct answer is B

Number of people playing both rugby and cricket = 4 Number that play cricket only = 11 - 4 = 7 Number that play rugby only = 14 - 4 = 10. Number that play for at least one of the teams = 4 + 7 + 10 = 21.

1,422.

Simplify \(\frac{\sqrt{12} - \sqrt{3}}{\sqrt{12} + \sqrt{3}}\)

A.

\(\frac{1}{3}\)

B.

9

C.

16cm

D.

3

Correct answer is A

\(\frac{\sqrt{12} - \sqrt{3}}{\sqrt{12} + \sqrt{3}}\)

\(\sqrt{12} = \sqrt{4 \times 3} = 2\sqrt{3}\)

\(\therefore \frac{\sqrt{12} - \sqrt{3}}{\sqrt{12} + \sqrt{3}} = \frac{2\sqrt{3} - \sqrt{3}}{2\sqrt{3} + \sqrt{3}}\)

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

= \(\frac{1}{3}\)

1,423.

Evaluate \(\frac{(81)^{\frac{3}{4}} - (27)^{\frac{1}{3}}}{3 \times 2^3}\)

A.

27

B.

1

C.

\(\frac{1}{3}\)

D.

\(\frac{1}{8}\)

Correct answer is B

\(\frac{(81)^{\frac{3}{4}} - (27)^{\frac{1}{3}}}{3 \times 2^3}\)

= \(\frac{(3^{4})^{\frac{3}{4}} - (3^{3})^{\frac{1}{3}}}{3 \times 2^{3}}\)

= \(\frac{3^{3} - 3^{1}}{24}\)

= \(\frac{27 - 3}{24} = 1\)

1,424.

Express the product of 0.0014 and 0.011 in standard form

A.

1.54 x 10-2

B.

1.54 x 10-3

C.

1.54 x 10-4

D.

1.54 x 10-5

Correct answer is D

\(0.0014 = 1.4 \times 10^{-3}\)

\(0.011 = 1.1 \times 10^{-2}\)

\(\therefore 0.0014 \times 0.011 = 1.4 \times 10^{-3} \times 1.1 \times 10^{-2}\)

= \(1.54 \times 10^{-5}\)

1,425.

A worker's present salary is N24,000 per annum. His annual increment is 10% of his basic salary. What would be his annual salary at the beginning of the third year?

A.

N28,800

B.

N29,040

C.

N31,200

D.

N31,944

Correct answer is B

Present salary = N24,000.

Increment after first year = \(\frac{10}{100} \times N24,000 = N2,400\)

Salary at the beginning of second year = N(24,000 + 2,400)

= N26,400.

Increment after second year = \(\frac{10}{100} \times N26,400 = N2,640\)

Salary at the beginning of third year = N(26,400 + 2,640)

= N29,040.

\(\therefore\) His salary at the beginning of the third year = N29,040.