PLEASE HELP ME I NEED THIS ANSWER PLS PLs

There is an 18 month no-interest promotion and $200 cash reward if you spend
$1,000 in the first 80 days. You decide to spend $1,000 in the first 80 days. You
continue to spend for the next 18 months. At the end of 18 months, you have a
balance of 2,000. The interest rate is now 16% on your balance. You have been
saving $200.00 a month for the last 18 months at .01 interest.

You decide to take the money you were saving for the car to pay off your credit
card.
2) How long will it take you to pay off your balance (no new spending)?

1) How much interest will you pay? use link for more info https://www.bankrate.com/finance/credit-cards/credit-card-payoff-calculator/

3) How much of the $200 cash reward did you actually get to keep?

4) What is the opportunity cost of paying off your credit card balance?