Math, asked by saahil1703, 1 year ago

find the value of 81+27+9+.....1/27.. the no.s are in G.P.

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Answers

Answered by channa21
2
last term of GP(Tn) =ar^n-1
1/27=81*1/3^n-1
1/27*1/81=1/3^n-1
1/2187=1/3^n-1
1/3^7=1/3^n-1
n-1=7
n=8
sum of GP (Sn) =[a(1-r^n)]/(1-r)
Sn=[81(1-1/3^8)]/1-1/3
Sn=81(65611/65612)/2/3
Sn≈243/2
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