1. Each train is loaded with X tons of chemical fertilizer, and each carriage is loaded with Y tons of chemical fertilizer.

6x+ 15y=360 1

8x+ 10y=440 2

X=60-5/2Y 3 from 1.

Substituting 3 into 1 gives 8(60-5/2y)+ 10Y=440.

480-20y+ 10y=440

- 10y=-40

y=4

Substituting Y=4 into 3 gives X=60- 10=50.

So each train carries 50 tons of leather and each car carries 4 tons.

2. Let's buy X tickets for Class A and Y tickets for Class B, according to the meaning in the question.

X+Y=35

24X+ 18Y=750

X=20 as above.

Y= 15

So buy 20 class A tickets, 15 class B tickets.

3. The number of people going to Yunshui Cave is X, and the number of people going to Huagongling is Y.

X+Y=200

Y=2X- 1

X=67 as above.

Y= 133

So there are 67 people in Yunshui Cave and 133 people in Huagongling.