 Hello and welcome to the session I am Deepika here. Let's discuss a question which says if Nina gives an interest of rupees 45 for one year at 9% rate per annum, what is the sum she has borrowed? Now we know that for the sum borrowed, the interest for one year is given by interest is equal to principal into rate upon 100. So this is the key idea behind our question. We will take the help of this key idea to solve the above questions. So let's start the solution. Now we are given an interest of rupees 45 that is interest is equal to rupees 45 for one year at 9% rate per annum that is rate is equal to 9% per annum. The idea we have is equal to principal into rate upon 100. We want to find the principal or the sum borrowed. So principal is equal to interest into 100 equal to rupees 45 into 100 upon rate is 9% per annum. So on cancellation we have therefore principal is equal to rupees 500. Since the sum Nina has borrowed is rupees 500 and this is our answer. I hope the solution is clear to you. Bye and take care.