Colin and Cass take out a loan of $240000 over 20 years at 7.2% p.a. compounding monthly. Their monthly repayment on this loan is $1890. a Calculate the total amount they will pay for this loan. b After 36 months of repaying the loan, the amount still owing is $221977. Colin and Cass then pay a lump sum of $30000 off their loan. How much is still owing after making this lump-sum payment? c If they continue to pay off the loan at $1890 each month it will take them another 13 years and 1 month to repay the loan completely. How much do they save by making the lump-sum payment