1, solution: the fabrics of the cut coat and trousers are x meters and y meters respectively.

x+y= 15

X=2y (one coat or two pairs of trousers can be cut per 1m fabric. In order to match the coat with the trousers, the cloth of the coat is cut twice as much as that of the trousers.

The solution is x= 10.

y=5

Therefore, the fabrics of the cut coat and trousers are10m and 5m respectively.

2. Solution: Let the speeds of Party A and Party B be X km/h and Y km/h respectively.

5(x+y)=25

5x+3(x+y)=25 (sum of distances equals total distance).

The solution is x=2.

y=3

So the speeds of Party A and Party B are 2 km/h and 3 km/h respectively.

3. Solution: Let two people make X and Y parts every day.

2x+2(x+y)=350

2y+3(x+y)=350

The solution is x=75.

y=25

So they produce 75 and 25 parts every day.