all we have to do is set this up! we know that all he practiced altogether for 15 and 1/3 hours so lets put that down so far 1 15 ----- = 3 and he says that the first week he played 6 and 1/4 hours on the first week now lets add that 1 1 15 ----- = 6 ----- + 3 4 now we also know that he played 4 and 2/3 hours on the first week now lets add that 1 1 2 15 ----- = 6 ----- + 4 ----- + 3 4 3 we arent finished yet! now the third week we dont know how long he played so we are going to put x in its place 1 1 2 15 ----- = 6 ----- + 4 ----- + x 3 4 3 and there is your answer! finally... hope this helps:) MARK AS BRAINLIEST!!! :D