Question

If k, 2k-1 and 2k+1 are three consecutive terms of an arithmetic progression,the value of k is ___

Answer 1

First term ( T1 ) = K


Second term ( T2 ) = 2K - 1


And,


Third term ( T3 ) = 2K + 1



Common difference ( D ) = T2 - T1


=> 2K - 1 - K


=> ( K - 1 )

Also,


Common difference ( D ) = T3 - T2



=> 2K + 1 - ( 2K - 1 )


=> 2K + 1 - 2K + 1



=> 2.


As we know that , common difference of an AP is always equal .


So,


T2 - T1 = T3 - T2




K - 1 = 2


K = 2 + 1


K = 3.

Answer 2

So right answer. is K=3.