document.write( "Question 1118180: Andrew recently opened a barbershop and is trying to figure out how much shaving cream he should buy on a regular basis. He has found that for the first two months the probability that a customer needs a haircut is 0.6, the probability that a customer needs a shave is 0.4, and the probability that a customer needs a haircut or a shave is 0.9. What is the probability a customer will need both a haircut and a shave? \n" ); document.write( "

Algebra.Com's Answer #733440 by Boreal(15235) $\"\"$ $\"About$

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P(A or B)=P(A)+P(B)-P(A and B), where A is haircut and B is a shave.
\n" ); document.write( "0.9=0.6+0.4-P(A and B)
\n" ); document.write( "P(A and B)=0.1 \n" ); document.write( "

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