# Misc 2 - Chapter 9 Class 11 Sequences and Series

Last updated at Dec. 8, 2016 by Teachoo

Last updated at Dec. 8, 2016 by Teachoo

Transcript

Misc 2 If the sum of three numbers in A.P., is 24 and their product is 440, find the numbers. Let the three numbers in A.P. be a d, a, a + d. Sum of the three numbers is 24 (a d) + (a) + (a + d) = 24 a + a + a + d d = 24 3a + 0 = 24 3a = 24 a = 24/3 a = 8 Also, it is given that product of three number is 440 i.e. (a d) (a) (a + d) = 440 (a d)(a + d)a = 440 (a2 d2)a = 440 Putting a = 8 (82 d2)8 = 440 82 d2 = 440/8 64 d2 = 55 64 55 = d2 9 = d2 d2 = 9 d = 9 d = 3 So, d = 3 , d = 3 When d = 3 & a = 8 The numbers are a d = 8 3 = 5 a = 8 a + d = 8 + 3 = 11 Hence the numbers are 5, 8, 11 When d = -3 & a = 8 The number are a d = 8 (-3) = 8 + 3 = 11 a = 8 a + d = 8 + (-3) = 8 3 = 5 Hence the numbers are 11, 8, & 5 Hence the numbers are 5, 8, 11 for a = 8, d = 3 and 11, 8, & 5 for a = 8, d = -3

Miscellaneous

Misc 1

Misc 2 You are here

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

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.