Question

A quantity x varies directly with y and inversely with z. Which expression represents the constant of variation, k?

Answer 1

A quantity x varies directly with y and inversely with z. Which expression represents the constant of variation, k?

xz/y

xy/z

z/xy

y/xz

Answer 2

This is a question on joint variation.

Direct variation is as follows :

x varies directly as y is written as follows :

x/y = k

x varies inversely as z is written as follows :

xz = k

now in both cases :

x = yk and x = k/z respectively.

Combining the two we have :

x = ky/z