((7 + 5)^2) / (4 * 3 + 9) =
(12^2) / (12 + 9) =
144 / 21 reduces to 48/7 or 6 6/7
To get the answer we can use proportion.
30----------100%
12-----------x
Cross multiply now
30x=12*100%
30x=1200% /:30 (divide both sides by 30)
x=40% - it's the percentage of cars which finished the race.
100%-40%=60% - it's the answer
