Probability question:

A bag contains 12 coloured balls. Five of the balls are red and the rest are blue. A ball is drawn at random from the bag. It is then replaced and a second ball is drawn. The colour of each ball is recorded.
The first question asks me to list the possible outcomes of the experiment which I did without problems. The next one however, is where I am stuck.
(b) Calculate the probability that:
(i) The first ball is blue

Question

Probability question:

A bag contains 12 coloured balls. Five of the balls are red and the rest are blue. A ball is drawn at random from the bag. It is then replaced and a second ball is drawn. The colour of each ball is recorded.
 The first question asks me to list the possible outcomes of the experiment which I did without problems. The next one however, is where I am stuck.
(b) Calculate the probability that:
(i) The first ball is blue

solomonzelman · Answer

5 - red
12-5=7 blue

Ball is randomally drawn twice with replacement.

solomonzelman · Answer

BR
BB
RB
RR

those are possible outcomes,
(and would have been even without replacement)

solomonzelman · Answer

(b) probability of what?

anonymous · Answer

The probability that the first ball is blue

anonymous · Answer

The answer is given as 7/12 but I don't know how they got there

zarkon · Answer

7 blue out of 12balls

anonymous · Answer

Oh...I don't know how I missed that...

anonymous · Answer

Well ok then. Thanks very much.

zarkon · Answer

no problem