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
Answer:
121.205882353
Step-by-step explanation:
Put it in a calculator
Length (L): 2w + 3
width (w): w
border (b): 
Area (A) = (L + b) * (w + b) <em>NOTE: This is assuming the width also has a border</em>
= (2w + 3 +
) * (w +
)
= 

= 

= 
Answer:
20 cups
Step-by-step explanation:
16 ounces = 1 pound
8 ounces = 1 cup
16 ounces = 2 cups
1 pound = 2 cups
10 pounds = 20 cups
The sum of the inner angles of any triangle is always 180°, i.e. you have

In the particular case of an equilater triangle, all three angles are the same, so

and the expression becomes

which implies 
So, if you rotate the triangle with respect to its center by 60 degrees, the triangle will map into itself. In particular, if you want point A to be mapped into point B, you have to perform a counter clockwise rotation of 60 degrees with respect to the center of the triangle.
Of course, this is equivalent to a clockwise rotation of 120 degrees.
Finally, both solutions admit periodicity: a rotation of 60+k360 degrees has the same effect of a rotation of 60 degrees, and the same goes for the 120 one (actually, this is obvisly true for any rotation!)