18/2 (2a+17*3) = 549
so, a = 5
Now just find
a56 = a+55d
S32 = 32/2 (2a+31d)
The sum of 18 terms of an A.P is 549. Given that the common difference is 3, find the 56th term and also the sum of the its 32 terms.
1 answer
1 answer