A bag contains 3 red balls and 3 blue balls. 2 balls are selected at random. How do you find the probability of selecting 2 red balls?

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Answer 1 · 2016-12-29T20:05:34

#P(R,R) = 1/5#

With probability always think of things happening one event at a time.

There are 6 balls altogether, 3 of which are red.

Take the first ball:

#P(Red) = 3/6#

Now there are 5 balls left, 2 of which are red.

Take the second ball:

#P(Red) = 2/5#

Therefore #P(R,R) = 3/6 xx2/5#

Simplify# cancel3/cancel6^cancel2 xxcancel2/5#

#P(R,R) = 1/5#