Last updated at May 29, 2018 by Teachoo

Transcript

Misc 27 A farmer buys a used tractor for Rs 12000. He pays Rs 6000 cash and agrees to pay the balance in annual instalments of Rs 500 plus 12% interest on the unpaid amount. How much will be the tractor cost him? Amount paid to buy tractor = Rs 12,000 He pays cash = Rs 6000 Remaining balance = 12000 – 6000 = 6000 Annual instalment = Rs 500 + interest@12% on unpaid amount Thus, our instalments are 1220, 1160, 1100,…. Total number of instalments = (𝑅𝑒𝑚𝑎𝑖𝑛𝑖𝑛𝑔 𝑏𝑎𝑙𝑎𝑛𝑐𝑒 𝑙𝑒𝑓𝑡)/(𝐵𝑎𝑙𝑎𝑛𝑐𝑒 𝑐𝑙𝑒𝑎𝑟𝑒𝑑 𝑝𝑒𝑟 𝑖𝑛𝑠𝑡𝑎𝑙𝑚𝑒𝑛𝑡) = 6000/500 = 12 Thus, our instalments are 1220, 1160 , 1100 , … upto 12 terms We can observe that this is an AP as difference between consecutive terms is an AP Here first term (a) = 1220 common difference = d = 1160 – 1220 = – 60 number of terms = n = 12 We need to calculate total amount paid in 12 instalments i.e. (1220 + 1160 + 1100 + … upto 12 terms) We use the formula, Sn = 𝑛/2 (2a + (n – 1)d) Where, Sn = sum of n terms of A.P. n = number of terms a = first term and d = common difference Putting value of n = 12 , a = 1220 & d = –60 S12 = 12/2 [ 2(1220)+(12 – 1) (– 60) ] = 6[ 2440 + (– 60)11] = 6[ 2440 – 660] = 6 (1780) = 10680 Hence total amount paid in 12 instalments = Rs 10680 Hence, Total cost of tractor = Amount paid earlier + Amount paid in 12 instalments = Rs (6000 + 10680) = 16680

Miscellaneous

Misc 1

Misc 2

Misc 3 Important

Misc 4

Misc 5

Misc 6

Misc 7 Important

Misc 8

Misc 9

Misc 10

Misc 11

Misc 12

Misc 13

Misc 14

Misc 15

Misc 16 Important

Misc 17

Misc 18

Misc 19 Important

Misc 20

Misc 21

Misc 22

Misc 23

Misc 24

Misc 25 Important

Misc 26

Misc 27 You are here

Misc 28 Important

Misc 29

Misc 30

Misc 31

Misc 32 Important

About the Author

Davneet Singh

Davneet Singh is a graduate from Indian Institute of Technology, Kanpur. He has been teaching from the past 10 years. He provides courses for Maths and Science at Teachoo.