Answer:
21/70=x/30
Explanation:
Noticing that it is referring to problem b, we head over to that. It states two important pieces of information. Only seventy percent of the players participated, and 21 total played. This means we can simply divide 21 by 7, and multiply by 10. This shows us that there are thirty total players because 21/7 is equal to 3, multiplied by 10 is equal to thirty. 30 minus 21 is equivalent to 9, meaning 9 players did not play. The proportion we would use for this is 21:70 equal to x:30. Cross-multiply, and we get 70x = 630. x = 9, thus proving our answer is correct.