Answer:
For each draw we have 5 options (we even can draw two times the same ball, because it is replaced), you also need to remember that the outcomes B1W1 and W1B1 are different, because the order is different.
Then the 25 possible outcomes, using the given notation, are:
B1B1, B1B2, B1W1, B1W2, B1W3
B2B1, B2B2, B2W1, B2W2, B2W3
W1B1, W1B2, W1W1, W1W2, W1W2
W2B1, W2B2, W2W1, W2W2, W2W3
W3B1, W3B2, W3W1, W3W2, W3W3