This is a fairly easy half-life problem
Each half-life reduces the radioactive material by one half.
So after 72 hours the radioactive material would have undergone 6 half-lives.
2^6 = 64.
So, there will be one sixty-fourth of the material left.
520 / 64 = 8.125 grams will remain.
radioactive decay is an exponential decay function.
Source:
http://www.1728.org/halflife.htm
Subtract 250-50 which equals 200 and then multiply it by 3 which is 600
3x+5x-12=180
8x=180+12
8x=192
x=192/8
x=24
angle 1 = 5x-12
=5(24)-12
=120-12
=108
angle 2= 3x =3*24=72
angle 1 = angle 9
angle 9= 108
5 times 10.50 = $52.5
An additional $45
3 times 22 = $66
An other additional $65
The total price her shopping list costs is 229.5
Now, $300 - $229.5 = $70.5
Teri will have $70.50 left after buying these items.
