Half lives of two isotopes X and Y of a material are known to be `2 xx 10^(9)` years and `4 xx 10^(9
Channel: Doubtnut
Date: 2020-01-26

Half lives of two isotopes X and Y of a material are known to be `2 xx 10^(9)` years and `4 xx 10^(9)` years respectively. If a planet was formed with equal number of these isotopes, then the current age of planet, given that currently the material has 20 % of X and 80 % of Y by number, will be