help plz... will give medals and fan...warning... its a hard question

Question

anonymous · Answer

The opening balance of one of the 31-day billing cycles for Clay's credit card was $3300, but after 15 days Clay made a payment of $1900 to decrease his balance, and it stayed the same for the remainder of the billing cycle. If his credit card APR is 28%, how much more in interest would he pay for the billing cycle with the previous balance method than with the adjusted balance method?

anonymous · Answer

plz?

anonymous · Answer

Do you know the formulas that are needed?

anonymous · Answer

kinda

anonymous · Answer

Well I don't really can you give me the formula you think it is?

anonymous · Answer

i dunno sorry

anonymous · Answer

Well I don't know even what to google to get a formula for that so I can't help :/

anonymous · Answer

alright thx