(1) One profit and one loss: (profit+loss) ÷ (initial points-points) = number of units.

(2) Double losses: (big losses-small losses) ÷ (initial points-re-points) = number of units.

(3) Double profit: (big profit-small profit) ÷ (initial points-re-points) = number of units.

Example 1. A production team plans to produce a batch of parts. If it produces 240 parts per hour, it can eventually produce more.

360, if only 185 is produced per hour, it will be less than the planned number 135. How many parts do you need to produce?

Solution:

240×〔(360+ 135)÷(240- 185)〕-360

= 240x9-360 = 1800 (piece)

A:

This batch of parts *** 1800.