Question

If x varies inversely as y and x=12 when y=3, what is the value of x when y=9?

Answer 1

When `y=9 ; x=4`

Explanation:

`x prop 1/y or x =k*1/y or xy =k` (k is the constant of proportionality)
`x=12` when `y=3 :.12*3=k or k=36`.Hence the variation equation is `xy=36` when `y=9 ; x =36/9=4`[Ans]