Question

a man is playing on a machine. He has a strict 25% chance each to get 1, 2 or 3-credit coins on a turn. He, however, must use one of his own 1-credit coins to play a turn( He can always exchange 3-credit coins for three 1-credit coins). Also, these are not exclusive chances. i.e, You may get all the 1, 2, and 3-credit coins on a single turn. What is the minimum number of credits he should start with, in all possible cases, in order to play atleast 14 rounds?(a round has 4 turns) Now, he said that he got a 74 credit-profit. How many turns could he have played?