In an inverse proportion,

When we multiply the first quantity by any constant k, then another quantity is divided by the same constant k.

Given,

Here, we see that in part (b) when we divide 30by 6, we will get 5.

So, in part(a), we will get the value of x.

i.e. x = 12×6 = 72

Similarly, in part(a) when we divide x i.e.72 by 9, we will get 8.

So, in part(b) we will get the value of y.

i.e. y = 5×9 = 45