Partial variation - Jamb Mathematics Past Questions and Answers

Question 1:

• JAMB 1982

The quantity y is partly constant and partly varies inversely as the square of x. With P and Q as constants, a possible relationship between x and y is

A. Y = Q + \(\frac{P}{x^2}\)
B. Y = Q + px
C. Y = \(\frac{PQ}{x^2}\)
D. Y = Q - \(\frac{P}{x^2}\)

Question 2:

• JAMB 1983

y varies partly as the square of x and partly as the inverse of the square root of x.Write down the expression for y if y = 2 when x = 1 and y = 6 when x = 4

A. Y = \(\frac{10x^2}{31} + \frac{52}{31\sqrt{x}}\)
B. Y = x² + \(\frac{1}{\sqrt{x}}\)
C. Y = x² + \(\frac{1}{x}\)
D. Y = \(\frac{x^2}{31} + \frac{1}{31\sqrt{x}}\)

Question 3:

• JAMB 1985

In a restaurant, the cost of providing a particular type of food is partly constant and partially inversely proportional to the number of people. If cost per head for 100 people is 30k and the cost for 40 people is 60k, Find the cost for 50 people?

A. 15k
B. 20k
C. 50k
D. 40k
E. 45k

Question 4:

• JAMB 1989

The cost of dinner for a group of students is partly constant and partly varies directly as the number of students. If the cost is N74.00 when the number of is 20 and N96.00 when the number is 30, find the cost when there are 15 students

A. N68.50
B. N63.00
C. N60.00
D. N52.00

Question 5:

• JAMB 2021

If w varies inversely as \(\frac{uv}{u + v}\) and w = 8 when

u = 2 and v = 6, find a relationship between u, v, w.

A. Uvw = 16(u + v)
B. 16uv = 3w(u + v)
C. Uvw = 12(u + v)
D. 12uvw = u + v