Probability of a tail for any on coin = 1/2
As the tosses of the 4 coins are independent of each other we multyiply the probs:-
P(4 tails) = 1/2 * 1/2*1/2*1/2 = 1/16
The answer is 3,072.
Heres how I got it:
SA of a CUBE: s^3 * 6
Lets plug in our numbers-
8 * 8 * 8= 512 * 6
512 * 6= 3072
2p+6a=$14
3p+9a=$21
3p+9a=21
Subtract 9a
3p=21-9a
divide all by 3
p=7-3a
plug it into start equations
2p+6a=14
2(7-3a)+6a=14
14-6a....+6a=14
this zeroes out...