# Probability

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• May 18th 2007, 12:41 PM
jarny
Probability
A customer enters a supermarket. The probability that the customer buys bread is .6, the probability that he buys milk is .5, and that he buys both bread and milk is .3. What is the probability that the customer would buy either bread or milk or both?
Help would be appreciated thanks!
• May 18th 2007, 01:45 PM
Soroban
Hello, jarny!

Quote:

A customer enters a supermarket.
The probability that the customer buys bread is 0.6,
the probability that he buys milk is 0.5,
and that he buys both bread and milk is 0.3.
What is the probability that the customer would buy either bread or milk or both?

You are expected to know this formula:
. . . P(B U M) .= .P(B) + P(M) - P(B ∩ M)

Therefore: .P(B U M) .= .0.6 + 0.5 - 0.3 .= .0.8

• May 18th 2007, 02:29 PM
jarny
thanks. Ya, i have never seen that formula before. Our teacher gives us extra credit for finding out things we haven't learned yet. We're supposed to look it up or find someone who knows how to do it. Thanks again