Seventy percent of the engines manufactured on an assembly line are defective. Suppose engines are randomly selected one at a ti
me and tested. Given that the first two engines tested were defective, what is the probability that at least two more engines must be tested before the first nondefective is found?
Substitute first Y for the second Y So it would be x + x + 6 = -2 Then it would be 2x +6 = -2 Move the 6 over so it would be 2x =-8 Divide by 2 your answer is x = -4