The half lives of radioactive elements `X` and `Y` are `3` mintue and `27` minute respectively. If the activities of both are same, then calculate the ratio of number of atoms of X and Y.

Answer

`1//9`

Explanation

Activity of x= Activity of y or `n_(x) lambda_(x)=n_(y) lambda_(y)`
`implies n_(x)[0.693/((T_(1//2))_(x))]=n_(y)[0.693/((T_(1//2))_(y))]`
`implies n_(x)/n_(y)=((T_(1//2))_(x))/((T_(1//2))_(y))=3/27=1/9`