What will come in place of the question mark (?) in each of the following series?
18, 2, 36, 3, 108, 4, ?, 5
432
The sequence is a combination of two series:- 18, 36, 108, ?.. and second: 2, 3, 4,..
The pattern followed in first is × 2, × 3, ...
Missing number = 108 × 4 = 432