Each car has at least 1 teacher * * * There are 6 teachers going out, so at most 6 cars are needed.

Suppose car A has car X and car B has car Y, then there are:

45x+30y & lt； Or = 234 400x+280y

So x=5 y= 1.

x=4 y=2

X=3 y=4 (s)

That is to say, there are only two options: one car, five cars, 1 car or one car, four cars and two cars.