Solution: Let the number of workers producing bolts be X and Y, and the equation is as follows:

50x=20y/2 ( 1)

x+y= 120 (2)

Brought in by y=5x of (1) (2)

x+5x= 120

6x= 120

X=20 people

Bring it in (2)

y= 120-20

= 100 people

A: There are 20 workers producing bolts and 65,438+000 workers producing bolts.