In the following question, select the missing number from the given series.
14, 6, 5, 6.5, 12, ?

a) 20
b) 17
c) 29
d) 25

Ans : 29

Solution :

14*(0.5) -1 = 7-1 =6
6*(1.0) -1 =6-1 =5
5*(1.5) – 1 =7.5-1 =6.5
6.5*(2)-1 =13-1=12
12*(2.5)-1=30-1=29