3(19-4)=2(19)+7
distribute the 3
57-12=38+7
45=45
Answer:
9 at minimum
Step-by-step explanation:
a minimum of 9 because it takes a total of 8 rides to take back a full 18 cars back and the 9th ride takes back the remainder which is 0.27777777778 times 18 cars
The answer is a whole number