Question 104879
The function A=A(base of 0)e^-0.01152x models the amount of pounds of a particular radioactive material stored in a concrete vault, where x is the number of years since the material wsa put into the vault. If 800 pounds of material are initially put into the vault, how many pounds will be left after 180 years? 
:
Get to know the formula:
A = Ao*(e^-.01152x)
Where:
Ao = original amt (800 lb in this problem)
A = resulting amt
x = years of decay (180 yrs in this problem)
:
A = 800(e^(-.01152*180))
A = 800(e^-2.0736)
On good calc find e^-2.0736, should get: .12573, so you have:
A = 800 * .12573
A = 100.586 lb remaining after 180 yrs