Joint variation - Jamb Mathematics Past Questions and Answers

Question 1:

• JAMB 1979

The mean of the numbers 1.2, 1.0, 0.9, 1.4, 0.8, 0.8, 1.2 and 1.1 is

A. 1.5
B. 0.8
C. 1.0
D. 1.02
E. 1.05

Question 2:

• JAMB 2013

P varies jointly as m and u, and varies inversely as q. Given that p = 4, m = 3 and u = 2 and q = 1, find the value of p when m = 6, u = 4 and q =\(\frac{8}{5}\)

A. 12\(\frac{8}{5}\)
B. 15
C. 10
D. 28\(\frac{8}{5}\)

Question 3:

• JAMB 2013

If r varies inversely as the square root of s and t, how does s vary with r and t?

A. S varies inversely as r and t²
B. S varies inverely as r² and t
C. S varies directly as r² and t²
D. S varies directly as r and t

Question 4:

• 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 5:

• 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. \(\frac{1}{81}\)