Josh works in a balloon store. he will put 45 balloons into bunches. he most use the same number of balloons in each bunch. the number of ballons in each bunch must be greater than 1 and less than 10.how many balloons could be in each bunch

You need to word this question a bit better. You said he mostly used the same number each time, meaning some bunches had a different number - meaning it could be practically any answer between 2-9. 

Assuming each bunch had the same number, however, we can find and exact answer. 

The way to do this is to see which of the possible choices go into 45 evenly.
45 is not even, therefore it cannot be 2
4+5=9***
4 is even and the ones digit is not 04 or 8 so it cannot be 4 
The ones digit is 5***
It is not divisible by 2 or 3 so I cannot be 6
It is not divisible by 7
It is not divisible by 8
4+5=9. 9 is divisible by 9***

The possible numbers in each bunch are 3, 5, and 9