 Hi and welcome to the session, I am Asha and I am going to help you with the following question which says, Shamsad Ali buys a scooter for Rs 22,000. He pays Rs 4,000 cash and agrees to pay the balance in annual installments of Rs 1,000 plus 10% interest on the unpaid amount. How much will the scooter cost him? Let's now start with the solution. And here the cost price of the scooter is Rs 22,000. Cash down payment is equal to Rs 4,000. So the amount to be paid in installments is Rs 22,000 minus Rs 4,000. So the balance amount in installments is equal to Rs 22,000 minus Rs 4,000 which is equal to Rs 18,000. Now let us find the annual installments. First installment is equal to Rs 1,000 plus 10% of the unpaid amount and the unpaid amount is Rs 18,000. So this is further equal to Rs 1,000 plus 10% 100 into 18,000 which is equal to Rs 1,000 plus 18% 100 which is equal to Rs 2,800. Now let us find the second installment. Second installment will again be Rs 1,000 plus 10% of the unpaid amount and now the unpaid amount after deducting Rs 1,000 from 18,000 is 17,000. So this is further equal to Rs 1,000 plus 1,700 which is equal to Rs 2,700. Now let us find the third installment, percent of the unpaid amount which is Rs 16,000. So this is equal to Rs 1,000 plus 1,600 which is equal to Rs 2,600. And so the amount in installments Rs 800 plus Rs 2,700 plus Rs 2,600 plus so on and these installments are 18 in number. Since he has to pay 18,000 and monthly installment is Rs 1,000 therefore he has to pay 18 installments. Now the sum of this series we will find with the help of sum of AP series. Now where the first term is 2800 let us denote it by a and the common difference is minus 100. So the sum of this AP series is number of terms upon 2 into 2 times of 2800 plus number of terms minus 1 into minus 100. So this is further equal to 9 into 600 plus 17 into minus 100 which is equal to 9 into 5600 minus 1700 and this is equal to 9 into 3900 which is further equal to Rs 35,100. So this is the amount paid by him in installments. Now let us find the total price of the scooter which is equal to the cash down payment of Rs 4,000 plus the amount paid in installments which is 35,100. So this will be equal to 39,100 and therefore our answer is Shamsadali 39,100. So this completes the solution take care and have a good day.