[Applied statistics] The probability of increasing stock price.

A stock market investor owns a stock whose present value is $25. She has decided that she will definitely sell her stock if either the stock price goes up and becomes $35 or goes down and become $20. The probability that stock price goes up for $1 is 0.55 and the probability that stock price goes down for $1 is 0.45. What is the probability that she retires with making money (that is, she is retiring by selling stock with $35.)