Carcass wrote:
If the probability of Hank and Babe, two baseball players in the same MLB team, of hitting a home run in today's game is 0.3 and 0.2, respectively, what is the probability that at least one of them will hit a home run in today's game?
Given:
P(Hank hits home run) = 0.3, which means P(Hank does NOT hit home run) = 1 - 0.3 =
0.7P(Babe hits home run) = 0.2, which means P(Babe does NOT hit home run) = 1 - 0.2 =
0.8When it comes to probability questions involving "at least," it's best to try using the complement.
That is, P(Event A happening) = 1 - P(Event A
not happening)
So, here we get: P(at least 1 home run) = 1 -
P(not getting at least 1 home run)So, we can write: P(getting at least 1 home run) = 1 -
P(getting zero home runs)P(getting zero home runs)P(getting zero home runs) = (Hank does not get a home run
AND Babe does not get a home run)
= (Hank does not get a home run)
x P(Babe does not get a home run)
=
0.7 x 0.8=
0.56So, P(getting at least 1 home run) = 1 -
0.56 = 0.44