math of investment
posted by Anonymous .
Suppose the probability of a coin coming up heads is 2/5. The coin is tossed 4 times (the tosses are independent), and Jane will win $5 for each head. If all 4 tosses are heads, she will get $100 extra. She never loses money.
a)what is the probability that Jane will win at least $5?
b)What is the expected value of her winning?

Jane will win at least $5