People sometimes use credit cards to purchase items they can’t afford to pay for at the moment of purchase. if you’re one of these people, you should know that the monthly finance charge on credit purchases is based on percent. let’s say you have an outstanding balance of $800 on your credit card. the credit card company charges 1.6% per month. what finance charge will you have to pay for one month?

From my understanding, the credit card is $800 of use, if it isn't paid off then interest will be applied on top of the credit card for every month. 

If finance charge just means 'interest' then interest is based off the current debt balance on the credit card. Multiply that and wala! interest charge (finance charge i think)

800 * 0.016 = $12.80

Finance charge is $12.80 for that one month

Or

800 + 12.80 = $812.80 Finance charge (as a total owed in 1 month)
Hope this helps.

Ican't do any of the other stuff, but i can get you started. the answer, i believe, is $2.50.