Question

Suppose that r varies directly as p and inversely as q², and that r=27 when p=3 and q=2. How do you find r when p=2 and q=3?

Answer 1

When `p=2 ; q=3; r=8`

Explanation:

`rpropp ; r prop 1/q^2 :.r prop p/q^2 or r=k*p/q^2 ; r=27 ; p=3 and q=2 :. 27=k*3/2^2 or k=27*4/3=36`Hence the variation equation is `r=36*p/q^2 :.`When `p=2 ; q=3; r=36*2/3^2=8`[Ans]