A person took a loan of `Rs40000` at the rate of `10%` simple interest per annum to contruct a house. After `2` years he gave return `Rs20000` to the bank. After more `2` years what amount should he return to the bank so as to repay his completely?

Explanation

At the rate of `10%` per annum,
the simple interest of `Rs40000` in `2` years `=Rs(40000xx10xx2)/(100)=Rs8000`
When the person gave `Rs20000` to the bank, it will cut `Rs8000` from `Rs20000` as interest and the rest of the money, i.e., `Rs(20000-8000)=Rs12000` will be subtracted from the principal `Rs40000`.
Thus, for the next `2` years , the person will have to pay interest on the principal
`Rs(40000-12000)=Rs28000`.
Now, the simple interest of `Rs28000` in `2` years at the rate of `10%` per annum `=Rs(28000xx10xx2)/(100)`
`=Rs5600`
`:.` The total amount `=Rs(28000+5600)=Rs33600`
Hence, the person have to pay `Rs3300` to the bank after more `2` years so as to repay his loan completely.