In a game, an urn contains 5 red, 7 white numbered balls. A ball is drawn at random from the urn.

If the first ball is white, a second ball is drawn from the urn the colour of both balls is recorded.

If the first ball was red, it is returned to the urn and a second ball is drawn

Only the colour of this second ball is then recorded

Either way, after the second ball is drawn and colour recorded, the game stops

a)Draw a tree diagram describing this experiment

b) What is the probability that a red ball is recorded