Answer: 3/4
Step-by-step explanation:
If Jamal has 3 times as many cars as planes then we could represent it by the equation x + 3x = 20 where x is the number of planes and 3x is the number of cars.
x+ 3x =20 solve for x
4x = 20
x = 5
Number of planes = 5
Number of cars = 3(5) = 15
Now the ratio of his cars to the total model will be [tex]\frac{15}{20}[/tex] which reduces to 3/4.