Question

If in an ap 3rd term is 18,7th term is 30sum of its 17term is.

Answer 1

3rd term=18
a+2d=18

7th term =30
a+6d=30

a+6d-a-2d=30-18
4d=12
d=3

a+6d=30
a+18=30
a=12

17th term= a+16d
                  = 12+48
                   =60