If a companys average expected return is 10% per year, and the standard deviation of returns is 15% annually. What is the rough probability that the stock gains more than 40% next year?

1. 1%

2. 33%

3. 5%

4. 0.5%

5. 2.5%

This question need a clear mathematical and graphical explanation, only selecting an option will not be considered as a correct answer...