it depends if this is simple interest or compound simple interest is find 5% of 600 and every year just give you that 5% compound is find 5% then add that to 600, then next year find 5% of that new amount
so if simple 5% of 600=5/100 times 600=30 2 years so add 30 times 2=60 600+60=660 total
if compound 5% of 600=5/100 times 600=30 new amound=630 year 2 5% of 630=5/100 times 630=31.5 new amount=661.5
if simple interest then $660.00 if compound then $661.50