Answer:
The total loan cost formula is
total cost = (r*p*n) / 1- ((1+r)^-n)
r is rate p is principal and n is number of payments
rate is rate / 1,200 therefore r = .01
number of payments = 1.5 * 12 months per year = 18
total cost = (.01 * 600 * 18) / (1 -(1.01)^-18)
total cost = 108 / 0.1639826858
total cost = 658.6061172693
total cost = 658.61
Interest = 58.61
Source: http://www.1728.org/loanfrm4.htm
Step-by-step explanation: