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Last updated at Jan. 11, 2019 by Teachoo

Transcript

Misc 31 (Method 1) A manufacturer reckons that the value of a machine, which costs him Rs 15625, will depreciate each year by 20%. Find the estimated value at the end of 5 years. We use the formula A = P ("1 โ" ๐/100)^๐ Here, P = principal r = rate of depreciation n = number of years A be the depreciated value Putting values Depreciated value = 15625("1 " โ20/100)^5 = 15625("1 " โ1/5)^5 = 15625("1 " โ1/5)^5 = 15625 (4/5)^5 = (15625 ร 1024)/3125 = 5 ร 1025 = 5125 Thus, the depreciated value of the machine after 5 years is Rs. 5125 Misc 31 (Method 2) A manufacturer reckons that the value of a machine, which costs him Rs 15625, will depreciate each year by 20%. Find the estimated value at the end of 5 years. The series is 12500 , 10000, 8000,โฆ.. This is a G.P. as 10000/12500 = 0.8 & 8000/10000 = 0.8 So, common ratio = 0.8 & first term = a = 12500 We need to calculate amount at the end of 5th year i.e. a5 We know that nth term of GP is an = arn โ 1 Putting a = 12500, r = 0.8, n = 5 a5 = 12500(0.8)5 โ 1 = 12500(0.8)4 = Rs. 5120 Hence value of machine after 5 years is Rs. 5120

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 Not in Syllabus - CBSE Exams 2021

Misc 22

Misc 23 Not in Syllabus - CBSE Exams 2021

Misc 24 Not in Syllabus - CBSE Exams 2021

Misc 25 Important Not in Syllabus - CBSE Exams 2021

Misc 26

Misc 27

Misc 28 Important

Misc 29

Misc 30

Misc 31 You are here

Misc 32 Important

Chapter 9 Class 11 Sequences and Series

Serial order wise

About the Author

Davneet Singh

Davneet Singh is a graduate from Indian Institute of Technology, Kanpur. He has been teaching from the past 9 years. He provides courses for Maths and Science at Teachoo.