A radio isotope `X` with a half-life `1.4 xx 10^9` years decays of `Y` which is stable. A sample of the rock from a cave was found to contain `X` and `Y` in the ratio `1 : 7`. The age of the rock is.

A radio isotopesX with a half life 1.4xx10^9 years decays of Y which is stable . A sample of the rock from a cave was found to contain X and Y in the ratio 1:7 . The age of the rock is:

A radio isotope X with a half life 1.4xx10^(9) yr decays of Y which is stable. A sample of the rock from a cave was found to contain X and Y in the ratio 1:7 . The age of the rock is

A radio isotope X with a half life 1.4xx10^(9) yr decays of Y which is stable. A sample of the rock from a cave was found to contain X and Y in the ratio 1:7 . The age of the rock is

A radio isotope X with a half life 1.4xx10^(9) yr decays of Y which is stable. A sample of the rock from a cave was found to contain X and Y in the ratio 1:7 . The age of the rock is

A radioisotope Y with half-life 1.4xx10^9 years decays to X which is stable. A sample of the rock from a cave was found to contain X and Y in the ratio 1:7 . The age of the rock is - (A) 1.96 × 10^9 years. (B) 3.92 × 10^9 years. (C) 4.20 × 10^9 years. (D) 8.40 × 10^9 years.

A radioactive isotope X with a half-life of 1.37 xx 109 years decays to Y which is stable. A sample of rock from the moon was found to contain both the elements X and Y which were in the ratio of 1 : 7 . The age of the rock is.

A radioactive isotope X with a half-life of 1.37 xx 109 years decays to Y which is stable. A sample of rock from the moon was found to contain both the elements X and Y which were in the ratio of 1 : 7 . The age of the rock is.

A radioactive isotope X with half-life of 693xx10^(9) years decay to Y which is stable. A sample of rock from of the moon was found to contain both the elements X Y in the mole ratio 1:7 . What is the age of the rock ?