 Hello and welcome to the session. In this session we discuss the following question which says the price of a washing machine is $1000 cash or it may be paid for 5 equal monthly installments of $220 each. The first installment to be paid one month after purchase, find the rate of interest charged. Before we move on to the solution, let's discuss the formula to be used for equated time of payment. Consider P1, P2, P3 and so on with the different payments D1, D2, D3 and so on. And so, objectively, the equated time of payment which is donated by D is equal to P1, D1, D3 plus L upon P1 plus P2 plus P3 plus submission P. This is the key idea that we use for this question. As we see with the solution now, in the question we are given the price of the washing machine equal monthly installments of $220 each after the purchase. So, we have to find the rate of interest charged. First of all, we assume that the rate of purchase washing machine plus it's given in the question that each installment is of $220. So, where first we write the number of months that is D is done in this case, that is, now your next installment is also $220. And here D that is number of months would be $220, then D would be $320, then D would be $480. Then the last installment is also $220 and D is 5. Now, submission P is equal to, is equal to, we know that equated time of payment which is capital D is equal to submission PD upon submission P. Capital D is equal to submission PD upon submission P and again 3 times is 33. So, this is equal to 3. Capital D is equal to 3 months. How much do you get is obtained by adding the equated time that is capital D. Since we know that the zero date is the date of purchase of the washing machine. So, we get this is equal to $1100 minus the cost of the washing machine which is this is equal to $100. The total interest is equal to $100. First charge, we will find out $100 and this would be equal to this by 12 upon 3 equal to 3 upon 12 years, 1 year. These two zero cancels with these two zero, these zero cancels with these zero and 3, 4 times is 12. So, 4 into 10 is 40. So, this is equal to 40% the rate of interest. This can be easy session. Hope you understood the solution of this question.