Answer:
10
Step-by-step explanation: Because 10x2=20
so in this case if they were to push the tables togther only 1 can sit at one square table if there pushed together
unless each table held 2 people like one on one side and one on the other it would be the same formula because 10 on one side of the tables and 10 on the other side would be 10x2
10+10=20 or 10x2=20
ethier one would be the same
hope this helps you!