1 ÷ 5 = 1 in 5。
Total hours completed by apprentices.
1 ÷ 7 = 1 in 7。
Master and apprentice work together for 2 hours to complete the total
(0 of 65438+5+0 of 65438+7) × 2 = 24 of 35.
The total number of parts is
198 ÷ (0-24 of 65438+35) = 630 (piece)
The apprentice did it.
630× (1× 2 inch 7) = 180 (piece)