Suppose x and y are in an inverse proportion such that, when x = 15, then y = 8. Find the value of y when x = 20.

Given, $\mathrm{x} \propto \frac{1}{\mathrm{y}}$

=> x = $\frac{\mathrm{k}}{\mathrm{y}}$, where k is a constant.

=> k = xy

Substituting, x = 15 and y = 8, we get;

k = 15 x 8 = 120

Now, when x = 20, then;

=> 20 y = 120

=> y = $\frac{120}{20}$ = 6

That means when x is increased to 20 then y decreases to 6.