Request a call back

Join NOW to get access to exclusive study material for best results

CBSE Class 11-commerce Answered

find the sum of 7,77,777,7777,up to nth term
Asked by kbhavani936 | 19 Feb, 2024, 02:46: PM
answered-by-expert Expert Answer

S = 7 + 77 + 777 + 7777 + ............................ to n terms

S = 7( 1 + 11 + 111 + 1111 + ......................... to n terms  )

S = 7 [ 1 + (1+10) + (1+10+100 ) + (1+10+100+1000) + ......................to n terms  ]

In above expression , each term is geometric progression with first term = 1 and common ratio 10 .

img

where sr = 1 + 10 + 100 +  ............10r = ( 10r - 1 ) / (10-1) = (1/9) ( 10r - 1 )

img

img

 

 

Answered by Thiyagarajan K | 19 Feb, 2024, 06:10: PM

Application Videos

CBSE 11-commerce - Maths
Asked by ay608560 | 04 Mar, 2024, 05:10: PM
ANSWERED BY EXPERT ANSWERED BY EXPERT
CBSE 11-commerce - Maths
Asked by shivamkumar828786 | 04 Mar, 2024, 07:18: AM
ANSWERED BY EXPERT ANSWERED BY EXPERT
CBSE 11-commerce - Maths
Asked by kbhavani936 | 19 Feb, 2024, 02:46: PM
ANSWERED BY EXPERT ANSWERED BY EXPERT
CBSE 11-commerce - Maths
Asked by shikhapuri26 | 07 Sep, 2023, 04:05: PM
ANSWERED BY EXPERT ANSWERED BY EXPERT
CBSE 11-commerce - Maths
Asked by pgsrilakshmivenkateshwara | 16 Aug, 2023, 07:07: PM
ANSWERED BY EXPERT ANSWERED BY EXPERT
CBSE 11-commerce - Maths
Asked by slim16248 | 20 Oct, 2021, 12:28: PM
ANSWERED BY EXPERT ANSWERED BY EXPERT
CBSE 11-commerce - Maths
Asked by amarnath3473 | 13 Jun, 2021, 12:43: PM
ANSWERED BY EXPERT ANSWERED BY EXPERT
CBSE 11-commerce - Maths
Asked by Guptavanshika061 | 23 Apr, 2021, 12:12: PM
ANSWERED BY EXPERT ANSWERED BY EXPERT
CBSE 11-commerce - Maths
Asked by nikinikita0740 | 15 Feb, 2021, 09:12: PM
ANSWERED BY EXPERT ANSWERED BY EXPERT
CBSE 11-commerce - Maths
Asked by malikasaikia0 | 10 Dec, 2020, 12:02: PM
ANSWERED BY EXPERT ANSWERED BY EXPERT
Get Latest Study Material for Academic year 24-25 Click here
×