Adam is going to get a loan of £ 720 to help pay for the holiday. Adam will have to pay back the £ 720 plus interest of 15 %. He will pay this back in 12 equal monthly installments. How much money will Adam pay back each month?

From the question, we learn that Adam has take out a loan of £720. He will be paying back the loan in 12 monthly installments of the same amount each time. We are also told he must pay the loan back with 15% interest. So the 12 equal monthly payments must cover this cost therefore we must calculate this total payment first before calculating the monthly payment.

To work out the 15% increase of £720, we will split it into 10% and 5%. £720 is 100%. So to get from 100% to 10%, we divide by 10. So dividing the £720 by 10 gives £72. 5% is half of 10% so to work out 5% of £720, halve £72 to get £36. Then as 10%+5%=15%, we add £72 and £36 to get £108. Adding the 15% to the total 100% of £720 gives £720+£108=£828. So this is the total amount to be paid back and to calculate each 12 month payment, divide the total of £828 by 12 to get £69.