Carlos's credit card has an apr of 14.78% and a grace period of 18 days, and carlos pays his balance in full every month. if his last billing cycle ended on march 28, 2010, and he made his payment on april 13, 2010, did he owe any interest on his last statement's balance?

If Carlo’s last billing cycle ended on March 28, 2010, and he made his payment on April 13, 2010, he didn’t owe any interest on his last statement's balance because he paid within the grace period. I hope this helps and if you have any further questions, please don’t hesitate to ask again.

The expression of this would be 3.75x+y= 23

2.) is the most sense