math
posted by George .
The half life of iodine  131 is 8 days. How long will it take for 7/8 of the sample to decay?

That means 1/8 is left.
1/8=(1/2)^n
looks like n=3days
posted by George .
The half life of iodine  131 is 8 days. How long will it take for 7/8 of the sample to decay?
That means 1/8 is left.
1/8=(1/2)^n
looks like n=3days