Question

the first and last terms of an ap 17 350 if d=9,how many terms are therre and what is the sum

Answer 1

see pic for answer if its correct give thanks

Answer 2

We are given, a = 17, d = 9 and l = 350

So, AP is 17,26,35,.....350

Let there are n terms

Then, an = 350
    a + (n-1)d = 350
 so, 17 + (n-1)9 = 350
       (n-1)9 = 333
   = n-1 = 37
 so, n = 38

Hence, there are 38 terms in this AP

So, S = S38 = 38/2[a+l] = 19[17+350] 
          = 19*367 = 6973

Hence, Sum is 6973