# Should I use "portion" or "proportion"?

I have some balls, and some percentage q \in (0, 100%) of them are green (for example, q = 30% or 1/3). Should I say

"A portion q of the balls are green" or

"A proportion q of the balls are green"?

Or any other way I can express it clearly?

Thank you!

• @Jim Thank you for the comment. I am actually considering a mathematical expression, and whether I should say a portion q or proportion q, where q is a percentage. I have modified my question accordingly. May 2 at 5:24
• The word proportion could refer to the fraction of the balls that are green, but couldn't refer to the balls themselves. So, you could say The proportion of balls that are green is 30%. Otherwise, as Jim says,use a portion, which refers directly to the balls. May 2 at 10:16