Answer:
If a number is divisible by 10 (i.e. 100) then it is also divisible by 5.
Ex: 100 by 10, is 10 by 5, is 20
20 by 10 is 2 by 5 is 4
The number of times it is divisible by 5 will always be double the number of times it is divisible by 10, which makes sense because 10 is double 5.