JAMB Mathematics Past Questions & Answers - Page 323

1,611.

If log318 + log33 - log3x = 3, Find x.

A.

1

B.

2

C.

0

D.

3

Correct answer is B

log\(_{3}^{18}\) + log\(_{3}^{3}\) - log\(_{3}^{x}\) = 3

log\(_{3}^{18}\) + log\(_{3}^{3}\) - log\(_{3}^{x}\) = 3log33

log\(_{3}^{18}\) + log\(_{3}^{3}\) - log\(_{3}^{x}\) = log333

log3(\(\frac{18 \times 3}{X}\)) = log333

\(\frac{18 \times 3}{X}\) = 33

18 x 3 = 27 x X

x = \(\frac{18 \times 3}{27}\)

= 2

1,612.

Simplify \((\frac{16}{81})^{\frac{1}{4}} \div (\frac{9}{16})^{-\frac{1}{2}}\)

A.

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

B.

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

C.

\(\frac{8}{9}\)

D.

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

Correct answer is B

\((\frac{16}{81})^{\frac{1}{4}} \div (\frac{9}{16})^{-\frac{1}{2}}\)

\((\frac{16}{81})^{\frac{1}{4}} \div (\frac{16}{9})^{\frac{1}{2}}\)

\((\frac{2^4}{3^4})^{\frac{1}{4}} \div (\frac{4^2}{3^2})^{\frac{1}{2}}\)

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

\(\frac{2}{3} \div \frac{4}{3}\)

\(\frac{2}{3} \times \frac{3}{4}\)

\(\frac{2}{4}\)

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

1,613.

If the numbers M, N, Q are in the ratio 5:4:3, find the value of \(\frac{2N - Q}{M}\)

A.

2

B.

3

C.

1

D.

4

Correct answer is C

M:N:Q == 5:4:3

i.e M = 5, N = 4, Q = 3

Substituting values into equation, we have...

\(\frac{2N - Q}{M}\)

= \(\frac{2(4) - 3}{5}\)

= \(\frac{8 - 3}{5}\)

= \(\frac{5}{5}\)

= 1

1,614.

A man invested N5,000 for 9 months at 4%. What is the simple interest?

A.

N150

B.

N220

C.

N130

D.

N250

Correct answer is A

S.I. = \(\frac{P \times R \times T}{100}\)

If T = 9 months, it is equivalent to \(\frac{9}{12}\) years

S.I. = \(\frac{5000 \times 4 \times 9}{100 \times 12}\)

S.I. = N150

1,615.

Simplify \(\frac{3\frac{2}{3} \times \frac{5}{6} \times \frac{2}{3}}{\frac{11}{15} \times \frac{3}{4} \times \frac{2}{27}}\)

A.

\(5\frac{2}{3}\)

B.

30

C.

\(4\frac{1}{3}\)

D.

50

Correct answer is D

\(\frac{3\frac{2}{3} \times \frac{5}{6} \times \frac{2}{3}}{\frac{11}{15} \times \frac{3}{4} \times \frac{2}{27}}\)

\(\frac{\frac{11}{3} \times \frac{5}{6} \times \frac{2}{3}}{\frac{11}{15} \times \frac{3}{4} \times \frac{2}{27}}\)

\(\frac{110}{54} \div \frac{66}{1620}\)

50