1:4 tennis to soccer---- 1 =5 so 4 = 5x4=20 students on the soccer team
1:2 Soccer to football ----- 1=20 so 2= 20x2= 40 students on the football team.
there are 40!
let me know if you get it right
check the picture below.
so it has a base of 18x18 and a height of that much.

(1/4)x = 2
x = 8 x 3 = 24 feet long
(1/4)x = 1
x = 4 x 3 = 12 feet wide
24ft x 12ft = 288ft^2
That would be 40%
Explanation:
2 divided by 5= 0.4
Move the decimal to the right twice is 40%