Mark the correct alternative in the following:
If the sum of n terms of an A.P., is 3 which of its terms is 164?
Here, Sn=3n2+5n
∴ S1=3+5=8
∴ a1=S1=8
And S2=3×22+5×2=22
Now,a2=S2-S1=22-8=14
∴ d=a2-a1=14-8=6
Now, an=a1+(n-1)d
∴ 164=8+(n-1)6
∴ 156=(n-1)6
∴ 26=n-1
∴ n=27