Question

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 the given rock. The age of the rock
is estimated to be [2013]
(a) 60 years (b) 80 years
(c) 100 years (d) 40 years

Answer 1

Answer:

I think (b) ...............

Answer 2

Answer:

option a is a correct answer