What is the number of ways in which 20 identical toffees can be distributed among 10 students such that

1. Every student gets zero or more toffees.
2. Exactly 4 students get an odd number of toffees.

Use a calculator (an online one if the result is too large) to write only the answer.

Financial Maths

I bought a stock costing me Rs S(0). It is known that at the end of every year, the stock price will either rise by a factor of 'u' or fall by a factor of 'd'. 

Under these assumptions, there are only 4 stock prices possible after 3 years: 24, x, 32 and y.

What are x and y?