Since 3 3/4 equals 15/4, when you divide you have to switch the numbers in the divisor and then you turn the equation into multiplication.
So then it will be 15/4 x 4/3.
15 x 4 = 60
4 x 3 = 12 so the answer is 60/12. But you have to simplify so half of 60/12 is 30/6 and then half of 30/6 is 15/3 then you have to pick the gcf of 3 and 15 which is 3.