# A washing machine is available for Rs. 13,500 cash or Rs. 6,500 as cash down payment followed by three monthly instalments of Rs. 2,500 each. Find the rate of interest charged under instalment plan. In Solving this question Cash price of washing machine = Rs. 135000 Cash down payment = Rs. 6500 Balance due = Rs(13500 – 6500) = rs. 7000 No. of equal instalments = 3 Amountof each instalment =rs. 2500 Amount paid in installment = Rs. 7500 Therefore, interest paid in installment scheme = rs(7500-7000) = rs. 500 Principal for the 1stmonth = Rs. 7000 Principal for the 2ndmonth = Rs. 4500 Principal for the 3rdmonth = Rs. 2000 Total = Rs. 13500 Let the rate of interest be r% per annum I = p*r*1 / 1200 Then, I = 13500*r*1 / 100*12 => 500 =13500*r*1 / 100*12 =>r = 500*12/ 135 =>r = 44.4 % Why We Have Taken The Time As One Month

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Sorry Prakhar, I don't know the answer to your question but came to say you All the Best for Science Olympiad.. Do well :-)

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thanx a lot

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:-) Welcome :-)

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we have taken the time as 1 becoz it is given in the problem that the 3 instalments are paid in 3 consecutive months. that is 1 instalment in one month

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