Aman borrowed a sum of money and argues to pay rs4820 at the end if 2nd year and rs4200 at the end of the 3rd year to clear the debt it is compounded annually at 5% per annum .find the sum

In American English we'd use the word "amount" instead of "sum", and also we'd use the dollar symbol ($) instead of RS (rupees).  Instead of "argues," use the word "agrees."

A man borrowed a sum of money and agrees to pay $4820 at the end of the  2nd year and $4200 at the end of the 3rd year to clear the debt.  Interest is compounded annually at 5% per annum .find the original amount borrowed.