AP: 8.......350(Given)
A1=8
An=350
D. =9
So the AP is,
A2: a+d = 8+9=17
A3: a+2d = 8+2(9)=27
So we have the AP as 8,17, 26
Now we have to find number of terms present in the AP,
Using An=a+(n-1)d
350=8+(n-1)9
350-8=(n-1)9
342/9=n-1
38=n-1
n=39
Now, we found out the number of terms, that is 39 terms in total. The next step is calculating the sum of all the 39 terms, so
Using, Sn=n/2{2a+(n-1)d}
Sn = 39/2{2(8)+(39-1)9}
=39/2{16+342}
=39/2*358
=6981
Therefore, we got the sum as 6981
Hope my answer helps you!
Thank you.