power prep 2 leo

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by Brent@GMATPrepNow » Sun Dec 14, 2008 9:06 pm
The fastest way to solve this is to recognize that P(Leo hears a song he likes) = 1 - P(Leo likes none of the songs)

What is P(Leo likes none of the songs)?
For Leo to like no songs he must dislike the song on station A AND dislike the song on station B AND dislike the song on station C

The probability that all three of these events happening is (0.7)(0.7)(0.7)

So, P(Leo hears a song he likes) = 1 - P(Leo likes none of the songs)
P(Leo hears a song he likes) = 1 - (0.7)(0.7)(0.7)
P(Leo hears a song he likes) = 0.657

The answer is D

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by orel » Mon Dec 15, 2008 12:02 am
Hi,
OA is D

Thanks, Brent!