SOLUTION: A secretary has three telephones on her desk, each with a different number, and none is an extension. During a 15-second interval the probability that phone 1 will ring is 0.35, th

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Question 1022173: A secretary has three telephones on her desk, each with a different number, and none is an extension. During a 15-second interval the probability that phone 1 will ring is 0.35, that phone 2 will ring is 0.06, and that phone 3 will ring is 0.1. Find the probability that none of the phones will ring.

Answer by FrankM(1040) About Me  (Show Source):
You can put this solution on YOUR website!
We need to calculate "not ringing"
1 not ring = (1-.35)= .65
2 not ring = (1-.06) = .94
3 not ring = (1-.10) = .90
.65 * .94 * .90 = .5499 or 55% chance no phone rings.