Eight helicopters were part of the April 25, 1980 ill-fated attempt by the U.S. to rescue the Iranian hostages. At least six helicopters had to be operational for the mission to continue.

a) Suppose that the probability of failures for each helicopter during the mission is 0.10 and failures are independent of one another. What is the probability that three or more of the helicopters will fail?

b) What is the probability that the mission is successful?