Answers

2015-01-17T22:55:12+05:30
A + 2d =2k+1
k + 2 (k-1)= 2k+1
k + 2k -2 =2k+1
3k - 2=2k+1
k=3
2 5 2
2015-01-18T09:24:54+05:30
A series is said to be in AP when there is common difference between two consecutive term
therefore
2k-1-k=2k+1-(2k-1)
k-1=2
k=3
6 3 6