The half-life of a radioactive isotope `X` is `20 yr`. It decays to another element `Y` which is stable. The two elements `X` and `Y` were found to be in the ratio `1:7` in a sample of given rock. The age of the rock is estimated to be

The half-life of a radioactive isotope X is 20 years. It decays to another element Y which is stable. The two elements X and Y were found to be in the ratio of 1 : 7 in a sample of a given rock. The age of the rock was estimated to be.

The half-life of a radioactive isotope X is 50 years . It decays to another element Y which is stable . The two elements X and Y were found to be in the ratio of 1:15 in a sample of a given rock. The age of the rock was estimated to be

The half-life of a radioactive isotope X is 50 years. It decays to another element Y which is stable. The two elements X and Y were found to be in the ratio of 1 : 15 in a sample of a given rock. The age of the rock was estimated to be

The half-life of a radioactive isotope X is 50 years. It decays to another element Y which is stable. The two elements X and Y were found to be in the ratio of 1 : 15 in a sample of a given rock. The age of the rock was estimated to be

The half-life of a radioactive isotope X is 50 yr. It decays to an other element Y which is stable. The two elements X and Y were found to be in the ratio of 1 : 15 in a sample of a give rock. The age of the rock was estimated to be

The half life of a radioactive isotopes X is 50 years . It decays to another element Y which is stable . The two elements X and Y were found to be in the ratio of 1:15 in a sample of a given rock. The age of the rock was estimated to be :

The half-life of a radioactive isotope X is 50 yr. It decays to nother element Y which is stable. The two elements X and Y were found to be in the ratio of 1 : 15 in a sample of a give rock. The age of the rockwas estimated to be

The half life of a radioactive isotopes 'X' is 20 years . It decays to another element 'Y' which is stable . The two elements 'X' and 'Y' were found to be in the ratio of 1:7 in a sample of a given rock. The age of the rock was estimated to be :

The half life of a radioactive isotope X is 50 years. It decays to another element Y which is stable. The two elements X and Y were found to be in the ratio of 1: 15 in a sample of a given rock. The age (in years) of the rock was estimated to be