D. Rs.4634
Feedback Let P = Rs.100
Simple Interest = Rs. 80 ( ? 80% increase is due to the simple interest)
Rate of interest=(100×SI)/PT=(100×80)/(100×8) =10% per annum
Now let's find out the compound interest of Rs. 14,000 after 3 years at 10%
P = Rs.14000
T = 3 years
R = 10%
Amount after 3 years =P(1+R/100)^T
=14000(1+10/100)^3
=14000(110/100)^3
=14000(11/10)^3
=14×11^3=18634.
Compound Interest = Rs.18634 - Rs.14000 = Rs.4634