Max has 5 red cars 1/3 of the cars are red how many are left.

So 5 red cars
1/3 of all cars are red
therefor
5=1/3 of all cars
'of' means multply
5=1/3 times all cars
multiply both sides by 3
15=all cars

how many are left
basically how many are NOT red
15=all
red=5
all-red=others
15-5=others=10
10 cars are left

Do you have answer choices?