Question

Sum of n terms in an A.P. is 4nsquare-6.if k term is 107 find k?

Answer 1

Sn=4nsq-6

so, Sn-1=3 (n-1)sq-6

=4nsq +4n-8n -6

=4nsq -4n-6

now, Tn=Sn-Sn-1

=4nsq -6-(4nsq -4n-6)

=4n

let Tn be the k term,

Tn=107

4n=107

n=26.75 (not possible)

I think something is wrong in the question. The value of n will not be in fraction or in decimal.