Answer:
1/20, 0.05, 5%
Explanation:
There are 20 total possibilities, so you choosing one of them has a 1/20 chance. For example, If you had numbered the balloons, and you wanted to pick a red one with the number 3 on it, there would be a 1/20 chance. 1/20= 0.05, which also equals 5%
Hope this helps!