Hi please use the given information to answer each part of the problem and please include any drawing, or steps/formulas to improve my understanding of the problem if necessary. Thank you! Please do not repost response from other post.

A fixed amount a is placed in one envelope and an amount 5a is placed in the other. One of the envelopes is opened (each envelope is equally probable), and the amount X is observed to be in it. Let Y be the (unobserved) amount in the other envelope. (a) Find E (b) Find E Y (c) Find E(Y) E(X)