Suppose that 5 green balls and 12 purple balls are placed in an urn. two balls are then drawn in succession. what is the probability that the second ball drawn is a purple ball if the first ball is replaced before the second is drawn?

If the first ball is replaced and that we are not concern about the color of the first ball, then there is no concern for the first ball at all. 

Total number of balls = 5 + 12 = 17
Total number of purple balls = 12

P(second one is purple) = 12/17

Answer: 12/17