Let Xiao Wang make x parts every day, so Lao Wang makes (X+2) parts every day.
Then the number of parts that Lao Wang completed in 30 days: 30*(X+2),
Xiao Wang's work (30-5) = Number of parts completed in 25 days: 25*X
The number of parts completed by Xiao Wang is half that of Lao Wang, and the number of parts completed by Lao Wang is twice that of Xiao Wang, so there are:
25*X*2=30*(X+2)，
The solution is X=3.
So two people * * * completed the number of parts:
25*X+30*(X+2)=225
Further reading: How to buy insurance, which is good, and teach you how to avoid these "pits" of insurance.