e-value(expectation) and standard deviation of a distribution

Billy is collecting bottle caps from his favorite brand of soda pop. The company that produces it runs a contest: each bottle cap shows a picture of one of the 50 states of the United States, with each state equally likely. If you collect all 50 states, then you win a cash prize.

1. Find the e-value of your distribution of the number of bottle caps needed to get a full set of 50.

answers:
a) 204
b) 225
c) 286
d) 301


2. Find the standard deviation of your distribution of the number of bottle caps needed to get a full set of 50.

answers:
a) 62
b) 67
c) 74
d) 79