Mathematics 1981 Jamb Past Questions and Answers

Question 1 :

• JAMB 1981

Suppose x varies inversely as y, y varies directly as the square of t and x = 1, when t = 3. Find x when t = \(\frac{1}{3}\).

A. 81
B. 27
C. \(\frac{1}{9}\)
D. \(\frac{1}{27}\)
E. \(\frac{1}{81}\)

Question 2 :

• JAMB 1981

Suppose x varies inversely as y, y varies directly as the square of t and x = 1, when t = 3. Find x when t = \(\frac{1}{3}\).

A. 81
B. 27
C. \(\frac{1}{9}\)
D. \(\frac{1}{27}\)
E. \(\frac{1}{81}\)

Question 3 :

• JAMB 1981

If sine x equals cosine x, what is x in radians?

A. \(\frac{\pi}{2}\)
B. \(\frac{\pi}{3}\)
C. \(\frac{\pi}{4}\)
D. \(\frac{\pi}{6}\)
E. \(\frac{\pi}{12}\)

Question 4 :

• JAMB 1981

The ratio of the price of a loaf of bread to the price of a packet of sugar in 1975 was r : t. In 1980, the price of a loaf went up by 25% and that of a packet of sugar went up by 10%. Their new ratio is now

A. 40r:50t
B. 44r : 50t
C. 50r : 44t
D. 44r:55t
E. 55r:44t

Question 5 :

• JAMB 1981

Find a two-digit number such that three times the tens digit is 2 less than twice the units digit and twice the number is 20 greater than the number obtained by reversing the digits

A. 24
B. 42
C. 74
D. 47
E. 72