Question

If k,k2k-1 and 2k +1 are 3 consecutive terms of an ap then find k

Answer 1

a1=k,a2=2k-1,a3=2k+1

:-a2-a1=a3-a2

2k-1-2=2k+1-(2k-1)

K-1=2k+1-2k+1

K=1+1+1

K=3