Can you me with 20 and 22 you : )

So for 20. 250 is the starting amount of money put into the bank account, 35 is the amount added into the bank account and M is the number of months. So 35M would be the amount added to the bank account for however many months it has been. Does that make sense? If not maybe I can clarify something.

For the first question the answer is a, for the second c, for the third d, for the 4th b, for the 5th a