Answer:
The top lines in the middle of the envelope are 45 degree angles, and the rest are 180 degrees, and 90 degrees.
Step-by-step explanation:
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
1 kg = 2.20462 lbs
so 2.7 kg = 2.7(2.20462) = 5.952474....rounds to 5.95 lbs
