One half of a batch of parts can be finished in 18 days according to the plan. If the efficiency is improved by 1 / 8 after 3 days, the batch of parts can be finished How many days does it take for 1 / 3 of the total

One half of a batch of parts can be finished in 18 days according to the plan. If the efficiency is improved by 1 / 8 after 3 days, the batch of parts can be finished How many days does it take for 1 / 3 of the total

18 △ 1 / 2 = 36 days planned
1 / 3-1 / 36 × 3 = 1 / 4 the total amount to be completed in three days after the plan
1 / 36 × (1 + 1 / 8) = 1 / 32 current work efficiency
1 / 4 △ 1 / 32 = 8 days 8 + 3 = 11 days
A: it will take 11 days to complete 1 / 3 of this batch of parts

If you make a batch of parts, you can finish 1 / 2 of them in 18 days according to the plan. If the work efficiency increases by 1 / 8 after 3 days, you can finish 1 / 3 of these parts

Its original efficiency = (1 / 2) / 18 = 1 / 36
After the work efficiency is increased by 1 / 8, it is (1 / 36) * (1 + 1 / 8) = (1 / 36) * (9 / 8) = 1 / 32
One third of this batch of parts is completed, time = (1 / 3) / (1 / 32) = 32 / 3 days

After manufacturing a batch of parts, one third of it can be completed in 36 days according to the plan. After 12 days of actual work, the work efficiency has increased by 20%,
How many days will it take to actually complete this batch of parts?
Expression

36÷1／3=108
(1-12/108)÷[﹙1+20％﹚×1/108]+12=92
It took 92 days to actually complete this batch of parts