Solution:
Provided that,
The first term, a = 17
The last term, l = 350
The common difference, d = 9
If the A.P. has n terms, the formula for the last term can be expressed as;
l = a+(n −1)d
350 = 17+(n −1)9
333 = (n−1)9
(n−1) = 37
n = 38
Sn = n/2 (a+l)
S38 = 13/2 (17+350)
= 19×367
= 6973 As a result, this A.P. has 38 terms, and the total number of terms in this A.P. is 6973.