Solution: Let Lao Zhang actually do X, then Xiao Wang actually does (4/7X+2) and does the equation:

X-(4/7X+2)=30+2*20

Solution, X= 168

What Xiao Wang actually did: 168*4/7+2=98 (pieces)

168+98=266 (pieces)

A: There are 266 parts in this batch.

Hope to adopt