Select the number which can be replaced by the question mark (?) in the following series?
42, 14, 28, 7, 21, 4.2, ?
1
16.80
2
39.80
3
18.80
4
44.20
Select the number which can be replaced by the question mark (?) in the following series?
42, 14, 28, 7, 21, 4.2, ?