Sam takes out a £720 loan. Sam will have to pay back the £720 plus an interest rate of 15%. He will have to pay this back in 12 equal monthly instalments. How much must Sam pay monthly?

First, you must find out the total amount to pay back, this amount will be £720 + 15% of £720. To find 15% of £720, we first calculate 720/100 to find 1% and the multiply by 15: 720/100 = 7.2 *15 = 108. Now we know the interest amount we can do 720+108 to find the total amount payable as £828.

Now Sam has to pay £828 over 12 equal payments so once we calculate 828/12 as £69, we know that he must pay £69 per month for 12 months to pay off his loan.