Solution:
Principal =P= $ 7,500
Option A→(Simple interest)
Rate of interest= R=4%
Time()=4 years
Time()=6 years
Amount= Principal + Interest(Simple or compound interest)
Formula for Simple interest
Total amount after 4 years when interest is simple= 7500 +1200= $ 8700
Total amount after 6 years when interest is simple= 7500 +1800= $ 9300
Option B
Formula for amount(A) when interest is 3.15% compounded annually.
Total amount after 4 years when interest is compounded annually=$ 8491 (approx)
Total amount after 6 years when interest is compounded annually=$ 9034(approx)