A radioactive isotope `X` with a half-life of `1.37 xx 109` years decays to `Y` which is
Channel: Doubtnut
Date: 2020-01-19

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.