I know that if I want to simulate a value X it's X=F^-1(U). Just need some help as to what the limits are when I integrate f(x) to get F(X). Would they be 0 to 6 for x/36 and 6 to 12 for (12-x)/36? Because I thought one of the limits had to be x so that I would be able to substitute my U value to get X.

Thanks.