Each week Manhattan GMAT posts a GMAT question on our blog and follows up with the answer the next day. Are you up for the challenge?
A coin is weighted so that the probability of heads on any flip is 0.6, while the probability of tails is 0.4. If the coin is flipped 5 times independently, which of the following represents the probability that tails will appear no more than twice?
(A) (0.6)5 + 5(0.6)4(0.4) + 10(0.6)3(0.4)2
(B) (0.6)5 + 4(0.6)4(0.4) + 6(0.6)3(0.4)2
(C) (0.6)5 + 3(0.6)4(0.4) + 2(0.6)3(0.4)2
(D) (0.6)5 + 2(0.6)4(0.4) + (0.6)3(0.4)2
(E) (0.6)5 + (0.6)4(0.4) + (0.6)3(0.4)2