Doug C. answered • 08/05/18

Math Tutor with Reputation to make difficult concepts understandable

Hi Jovan,

One way to look at it:

You might try drawing a tree diagram where Even has a probability of 1/2 and Odd has a probability of 1/2.

Some possible outcomes {E,E,E}, {O,O,O}, {E,O,E}, etc. The probability of each of those outcomes is (1/2)(1/2)(1/2)= 1/8. If you list all possible outcomes there are actually 8 of them, so 1/8 as the probability for each outcome makes sense. Now how many outcomes have either two or three evens? EEE, EEO, EOE,OEE (OR 4 out of 8). I get a probability of 4/8 = 1/2.