Answer:
around 66% of their games
Step-by-step explanation:
So if we add 20 and 10 we get 30 which is the total amount of games played. We know that the team won 20 of the 30 games which we can reduce to 2/3. 2/3 is equal to 66.66 but most people just say 66% or you can round it up to 67%
Hope I helped!