JAMB Mathematics Past Questions & Answers - Page 361

1,801.

If log\(_{x^{1/2}}^{64}\)  = 3, find the value of x

A.

4

B.

16

C.

32

D.

64

Correct answer is B

If logx1/264 = 3
(X 1/2)3 = 64
(X 1/2)3 = 4 3
X 1/2 = 4
X = 42
X = 16

1,802.

simplify \(16^{\frac{-1}{2}}\times 4^{\frac{-1}{2}} \times 27^{\frac{1}{3}}\)

A.

3/8

B.

2/3

C.

3/4

D.

3/2

Correct answer is A

\(16^{\frac{-1}{2}}\times 4^{\frac{-1}{2}} \times 27^{\frac{1}{3}}\\
=\frac{1}{16^{\frac{1}{2}}}\times \frac{1}{4^{\frac{1}{2}}}\times 27^{\frac{1}{3}}\\
=\frac{1}{\sqrt{16}} \times \frac{1}{\sqrt{4}} \times sqrt[3]{27}\\
=\frac{1}{4} \times \frac{1}{2} \times \frac{3}{1}\\
= \frac{3}{8}\)

1,803.

The cost of kerosene per liter increased from N60 to N85. What is the percentage rate of increase?

A.

42%

B.

41%

C.

40%

D.

25%

Correct answer is A

N85 - N60 = N25 increase
∴percentage increase = \(\frac{25}{60}\times \frac{100}{1}\\=\frac{125}{3}\\=41.67%\\
=42%\)

1,804.

calculate the simple interest on N7,500 for 8 years at 5% per annum.

A.

N3,000

B.

N600

C.

N300

D.

N150

Correct answer is A

\(I = \frac{P \times T \times R}{100}\\
=\frac{7500 \times 8 \times 5}{100}\\
=N3000\)

1,805.

Express 123456 to 3 significant figures

A.

123000

B.

124000

C.

125000

D.

126000

Correct answer is A

123456 \(\approxeq\) 123000.