Question

If p varies jointly as m and r, and p = 180, when p = 5 and r = 8, then find m when p = 324 and

r = 6.

Answer 1

m = 12

Explanation:

If p varies jointly as m and r, then;

p = kmr

k is the proportionality constant

Given that p = 180, m = 5 and r = 8

180 = k(5)(8)

180 = 40k

k = 180/40

k = 4.5

To get m when p = 324 and r = 6

324 = 4.5(m)(6)

324 = 27m

m = 324/27

m = 12

Hence the value of m is 12