given a=8 an=62 sn=210 find n and d
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42
hey mate your answer is in image and first you use the formula of Sn=n/2(a+an) and you get n=6 then you use the formula of an =a+(n-1)d then you get d=54/5.
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Heya !!
First term ( A ) = 8
Last term ( An ) = 62
Sn = 210
N/2 × ( A + L ) = 210
N/2 × ( 8 + 62 ) = 210
N/2 × 70 = 210
N = 210/35
N = 6
Number of terms = 6
An = 62
A + ( N - 1 ) × D = 62
8 + ( 6 - 1 ) × D = 62
8 + 5D = 62
5D = 62 - 8
D = 54/5
Common difference ( D ) = 54/5.
First term ( A ) = 8
Last term ( An ) = 62
Sn = 210
N/2 × ( A + L ) = 210
N/2 × ( 8 + 62 ) = 210
N/2 × 70 = 210
N = 210/35
N = 6
Number of terms = 6
An = 62
A + ( N - 1 ) × D = 62
8 + ( 6 - 1 ) × D = 62
8 + 5D = 62
5D = 62 - 8
D = 54/5
Common difference ( D ) = 54/5.
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