I need help with number 3 on homework:

3. Let Y1, Y2, ..., Y, be a random sample from N(0, 1) and let Y10 be another independent random variable from N(0, 1). Let Y = =>?_, Y, and U = >?_, (Y, - Y)?. What is the distribution of? a) Y; b) U; c) T = ZZYZ; 9P d) V= U+Y 30 e) W = 4 + 16 U