RRB ALP || RRB RPF || RRB NTPC || MENTAL ABILITY || KANNADA || By Ningappa d n. 

It is arithmetic progression(AP) Tn=a+(n-1)d Where.. a=first term n=nth term d=difference between two consecutive numbers So… T16=6+(16-1)0.5 =6+7.5 =13.5 So answer is 13.5