Subscribe to our Youtube Channel - https://you.tube/teachoo

Last updated at Dec. 8, 2016 by Teachoo

Transcript

Ex 9.3 31 (Method 1) What will Rs 500 amounts to in 10 years after its deposit in a bank which pays annual interest rate of 10% compounded annually? We use the formula A = P ("1 + " 𝑟/100)^t Here, P = principal r = rate of interest t = time A be the amount Putting values Amount = 500("1 +" 10/100)^10 = 500 ("1 +" 1/10)^10 = 500 ((10 + 1)/10)^10 = 500 (11/10)^10 = 500 (1.1)10 Hence, amount is Rs 500 × (1.1)10 Ex 9.3 31 (Method 2) What will Rs 500 amounts to in 10 years after its deposit in a bank which pays annual interest rate of 10% compounded annually? The series is 550, 605, 665.5 … This is a G.P. as 605/550 = 1.1 & 665.5/605 = 1.1 So, common ratio = 1.1 & first term = a = 550 We need to calculate amount of 10th year i.e. a10 We know that nth term of GP is an = arn – 1 Putting a = 550, r = 1.1, n = 10 a10 = 550(1.1)10 – 1 = 550 (1.1)9 = (500 × 1.1)(1.1)9 = 500(1.1)(1.1)9 = 500(1.1)9 + 1 = 500(1.1)10 Hence amount in 10 years = Rs 500(1.1)10

Ex 9.3

Ex 9.3, 1

Ex 9.3, 2

Ex 9.3, 3 Important

Ex 9.3, 4

Ex 9.3, 5

Ex 9.3, 6

Ex 9.3, 7

Ex 9.3, 8

Ex 9.3, 9

Ex 9.3, 10

Ex 9.3, 11 Important

Ex 9.3, 12

Ex 9.3, 13

Ex 9.3, 14

Ex 9.3, 15

Ex 9.3, 16

Ex 9.3, 17 Important

Ex 9.3, 18 Important

Ex 9.3, 19

Ex 9.3, 20

Ex 9.3, 21

Ex 9.3, 22 Important

Ex 9.3, 23

Ex 9.3, 24

Ex 9.3, 25

Ex 9.3, 26

Ex 9.3, 27 Important

Ex 9.3, 28 Important

Ex 9.3, 29 Important

Ex 9.3, 30

Ex 9.3, 31 You are here

Ex 9.3, 32

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.