If 
is the amount of strontium-90 present in the area in year 
, and it decays at a rate of 2.5% per year, then
Let 
be the starting amount immediately after the nuclear reactor explodes. Then
or simply
So that after 50 years, the amount of strontium-90 that remains is approximately
or about 28% of the original amount.
We can confirm this another way; recall the exponential decay formula,
where is measured in years. We're told that 2.5% of the starting amount 
decays after 1 year, so that
Then after 50 years, we have
Answer:
please follow me am new on app please follow me please please
Step-by-step explanation:
also for watchers please follow me please
Answer:
The answer is 7
Step-by-step explanation:
25 times 25=625
24 time 24=576
625-576=7
And the square root of 49 is 7.
