On June 1, the garment factory produced 1200 sets of children's wear, 80 sets less in the first half than in the second half. How many sets in the second half?

1. If X sets are produced in the second half of the month, then X-80+X= 1200.

2X= 1280

X=640

2. If the father is X years old and the son is 46-X years old.

X+5-(46-X+5)=28

X-46+X=28

2X=74

X=37 years old

Then the son is 46-37=9 years old this year.

Five years later, the father is 37+5=42 years old and the son is 9+5= 14 years old.

3. If X baskets of pears are shipped, there are X+3 baskets of apples.

20(X+X+3)=480

40X+60=480

40X=420

X= 10.5

So pears have 10.5*20=2 10 kg, and apples have 480-2 10=270 kg.

4. If there are X kilograms left, sell X- 1200 kilograms.

X+X- 1200=4500*4

2X= 19200

X=9600

The remaining questions can be asked again. .