Help solve. Thanks

1. Let X and Y be independent random variables with the p.m.f. 2 3 4 5 f(x) 1/6 1/6 1/6 1/6 1/6 1/6 Use convolution to find the p.m.f. of T - X + Y. Why does the answer make sense? (Hint: X and Y represent the outcomes when you roll two fair dice.)