PLEASE SHOW WORK

1.) If you are saving $100 for one year with 10% annual interest rate, what is the interest earned on interest in your future value?

a) $20

b) 21

c) $0

d) $10

e) $1

2.) You have enrolled a retirement plan that guarantees to pay you a fixed amount for 25 years. At the time of retirement, you will have $100,000 to your credit according to the plan. The plan anticipates earning 7% interest annually over 25 years (compounded once a year). Assume the first payment begins from the first day of the retirement year, how much will your annual benefits be? (Supposedly the answer is PMT= -8019.675 but I don't understand how)

3.) Isaac only has $660 today but needs $1,000 to buy a new laptop. How many years will he have to wait to buy the laptop if he earns an annual interest of 10.5 percent, compounded monthly, on his savings? (Note: Keep two decimal places)