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Kumar buys a Maruti car for 2,40,000 at a down payment of R 1,20,000 and the rest inannual instalments of 10,000 plus 12% interest on the unpaid amount. Eventually whatwill the car cost him? |
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Answer» Given that the kumarpays Rs 120000 in cash.Therefore, unpaid amount = Rs 240000 – Rs 120000 = Rs 120000According to the given condition, the interest paid annually is12% of 120000, 12% of 110000, 12% of 100000, …, 12% of 10000Thus, total interest to be paid = 12% of 120000 + 12% of 110000 + 12% of 100000 + … + 12% of 10000= 12% of (120000 + 110000 + 100000 + … + 10000)= 12% of (10000 + 20000+ 30000 + … + 120000)Now, the series 10000, 20000, 30000 … 120000 is an A.P. with both the first term and common difference equal to 10000.Let the number of terms of the A.P. ben.∴ 120000 = 10000+ (n– 1) 10000⇒ 1 + (n– 1) = 12⇒n= 12∴Sum of the A.P =12[2(10000)+(12-1)(10000)]/2= 6[20000+110000]= 6(130000)= 780000Thus, total interest to be paid = 12% of (10000 + 20000 + 30000 + … + 120000)= 12% of 780000= Rs 93600Thus, cost of car= (Rs 240000 + Rs 93600) = Rs 333600 tq |
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