 Hi and welcome to the session. Let's work out the following question the question says the fan is available for rupees 970 cash Or rupees 210 as cash-down payment followed by three equal Monthly installments of rupees 260 each find the rate of interest charged under installment plan So let us start with the solution to this question let the rate of Interest be equal to our percent cash rise of Fan is Equal to rupees 970 cash-down payment is given to be rupees 210 Therefore balance amount is equal to rupees 970 minus rupees 210 that is equal to rupees 760 now Number of installments that is n is given to be equal to three and and monthly installments that is P is equal to rupees 260 Now under installments plan at the end of the scheme Amount of balance due is equal to future value of installments that is one plus and are divided by 1200 multiplied by balance amount is equal to One plus n minus one into our divided by 2400 Multiplied by n into P Or we can say one plus three into our divided by 1200 into 760 is equal to one plus three minus one that is to our divided by 2400 multiplied by three into 260 or One plus three are divided by 1200 multiplied by or we can say 1200 plus three are divided by 1200 multiplied by 760 is equal to one plus our by 1200 into 780 or 1200 plus three are multiplied by 760 is equal to 1200 plus our into 780 or 1200 plus three are multiplied by 76 by 78 is equal to 1200 plus our because we've taken 780 to the denominator here and We have 76 into 10 divided by 78 into 10 that becomes 76 by 78 Now this is same as 1200 plus three are into 38 by 39 is equal to 1200 plus our 1200 plus three are Multiplied by 38 is equal to 1200 plus our multiplied by 39 we've taken 39 to the right-hand side Now on opening the brackets. We have 45600 plus 114 are is equal to only 6800 plus 39 are or 114 are Minus 39 are is equal to 46,800 minus 45,600 or 75 are is equal to 1200 or our is equal to 1200 divided by 75 and that is equal to 16% So this is our answer to this question. I hope that you understood the solution and enjoyed the session. Have a good day