I am having trouble figuring out part D, any help would be welcomed!

Mario is setting up a money market savings account with an APR of 3.75% compounded monthly. He also received a $1,200 bonus for working extremely hard to complete a project ahead of schedule.

a. If he opens the money market savings account with his bonus money and then deposits $100 into the account every month, how much money will he have in this account in 5 years?

b. How long will it take for him to accumulate $6,000 for his dream vacation?

c. How much money will he need to deposit every month if he wants enough money to go on his dream vacation in just 3 years?

d. Mario decides that 3 years is too long to wait for his dream vacation. If he ups his monthly contributions to $190, what APR would he need to qualify for so that he can take his dream vacation in just 2 years?