Jamb Mathematics 1981 Past Questions and Answers

Question 16:

• JAMB 1981

A sum of money invested at 5% per annum simple interest amounts to $285.20 after 3 years. How long will it take the same sum to amount to $434.00 at 7\(\frac{1}{2}\)% per annum simple interest?

A. 7\(\frac{1}{2}\) years
B. 10 years
C. 5 years
D. 12 years
E. 14 years

Question 17:

• JAMB 1981

By selling an article for N45.00 a man makes a profit of 8%. For how much should he have sold it in order to make a profit of 32%?

A. N180.00
B. N59.00
C. N63.00
D. N58.00
E. N55.00

Question 18:

• JAMB 1981

An isosceles triangle of sides 13cm, 13cm, 10cm is inscribed in a circle. What is the radius of the circle?

A. 7cm
B. 12cm
C. 8cm
D. 7cm
E. 69cm

Question 19:

• JAMB 1981

A micrometer is defined as one millionth of a millimeter. A length of 12,000 micrometres may be represented as

A. 0.00012m
B. 0.0000012m
C. 0.000012m
D. 0.00000012m
E. 0.000000012m

Question 20:

• JAMB 1981

In one and a half hours, the minute hand of a clock rotates through an angle of

A. 90^o
B. 180^o
C. 640^o
D. 450^o
E. 540^o