If x varies inversely withy 3, and x=6 when y=3, find x when y=2.

Answer 1

x = k/y^3
6=k/27
k = 162

162/8 = 81/4

or, since xy^3 is constant, we have

(6)(27) = x(8)
x = 81/4

Answer 2

20.25