If an adult ticket costs $10, and a chlid's ticket is $5, then one possible combination of tickets could be 30 adult tickets and 10 children tickets. Another could be to sell 15 adult tickets and 25 children tickets.
If there are 250 tables you can multiply it by 4 to work with 1000. This means you have to multiply the other table cloth numbers. 150 x 4 = 600. 100 x 4 = 400. Once you simplify you can get 40 white and 60 red out of 100. 60/100 = 60%.