Question

If a=5 d=3 an=50 find n and sn

Answer 1

an =a+(n-1)d
50=5+(n-1)3
50=5+3n-3
50=2+3n
50-2=3n
48=3n
n=48/3
n=16

now,
sn=n/2(2a+(n-1)d )
sn=16/2(2×5+(16-1)3)
sn=8(10+15×3)
sn=8(25×3)
sn=8(75)
sn=600


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Answer 2

n = 16

Sn = 440 .

Here is ur answer .

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