Answer:
C.) 2
Step-by-step explanation:
<em>You must use the pythagorean theorem</em>
the distance on the x axis (or a) is 6
the distance on the y axis (or b) is 10
= 136
= 2
The distributive property:

After one half life it i s 130/2 = 65 g
after another 2 half lives it will be 65*1/2^2 = 16g to nearest gram
Simple multiplication so 3 x 24 = 72 so there are 72 boxes all together.