There are 3 red out of 7 total so red will be 3/7
There are 4 blue out of 7 total so blue will be 4/7
After he picks one he puts it back so every red will be 3/7 and every blue will be 4/7
B) multiply the probability of picking a red one by the probability of picking a red one again:
3/7 x 3/7 = 9/49 probability of picking 2 red ones.