Total loan amount = ₹5000
Amount paid back every month = ₹450
1 year = 12 months.
Total amount of money paid back in a year = ₹450 × 12 = ₹5400
Excess amount paid back = ₹5400 - ₹5000 = ₹400
The excess amount paid back to the bank is the interest amount.
So, the interest amount paid back is ₹400