JAMB Mathematics Past Questions & Answers - Page 102

506.

A man with an annual salary of N2000, has allowances of N600. If Income Tax is 5%. How much income tax expenses does he pay each year?

A.

15

B.

50

C.

70

D.

25

Correct answer is C

His annual salary = N2000 His allowances = N600 So his taxable income = Annual salary − allowance = N2000 − N600 = N1400 He pay at 5% Then, his allowance income tax 5/100 × 1400 = N70

507.

Simplify log101.5 + 3 log102 − log100.3

A.

log104

B.

log1040

C.

log10-40

D.

log104-

Correct answer is B

log101.5 + 3 log102 − log100.3

log101.5 + log1023 − log100.3

[log10(1.5 × 23) ÷ log100.3]

[log10(15/10 × 8 ) ÷ log10( 3/10)]

log10(15/10 × 8 × 10/3 )

log1040

508.

Find the x and z intercepts of the graph of 3x - z \(\leq\) 9

A.

(3, -9)

B.

(-3, 9)

C.

(-3, -9)

D.

(-3, 0)

Correct answer is A

Starting from 3x − z \(\leq\) 9

x = 0, substitute the value of x (i.e. x = 0) into the equation 3x − z \(\leq\) 9

3(0) − z \(\leq\) 9

z \(\leq\) − 9

If z = 0

Then, 3x − 0 \(\leq\) 9

3x \(\leq\) 9

x \(\leq\) 3

Intercept of x and z i.e (x,z)

= (3, -9)

509.
510.

In a town of 6250 inhabitants, there were 62 births during 1984. Find the percentage birth rate

A.

3%

B.

1.0%

C.

2.5%

D.

5.40%

Correct answer is B

Percentage birthrate = \(\frac{62}{6250} \times 100%\)

= \(\frac{6200}{6250}\)

= 0.992% \(\approx\) 1.0%.