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GRACE1962
May 25, 2009, 09:14 AM
Can someone please help me with this problem and explain how they came up with the answer?

A certain airlpane has two independent alternators to provide electrical power. The probability that a given alternator will fail on a one hour flight is .02. What is the probability that a) both will fail b) neither will fail c) one or the other will fail?

Any elp is appreciated!
Grace

Unknown008
May 25, 2009, 09:24 AM
a) When you have such probabilities, you need to think a while. You'll see that the probability of one of them fails is very small, 2/100. So, if both were to fail, would you add both, or multiply. Since one failing is small, the probability of both failing is smaller.

b) That is the same logic as in the first part.

c) When you have one or the other, You have to take a situation where one fails but not the other and then, that the other fails, not the one, if you can understand my point. If you named the first one A and the second one B, find the probability that A fails, not B and where B fails but not A, then add both values, since it is an option (confirmed by the word 'or')

Post back your answer.

Hope it helped! :)