In an A.P given a=8 , Tn=62 and Sn=210. Find n and d.
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Answered by
5
sn=n/2[2a+(n-1)]d use this formuls
RahulJaat1:
Nikal ke bta
n find karna or d bhe to formula nahi use kar sakta
first use ap= a+(n-1)d
second use n/2 (a+l)
Answered by
9
AP = a+(n-1)d
= 8 + (n-1)d ...........( i) eqe.
sum of AP = n/2(a+l)
= n/2 ( 8 + 62)
=n/2 (70)
210 = 35n
n = 210/35
n = 6 term ans..
= 8 + (n-1)d ...........( i) eqe.
sum of AP = n/2(a+l)
= n/2 ( 8 + 62)
=n/2 (70)
210 = 35n
n = 210/35
n = 6 term ans..
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