Master Feng intends to process a batch of parts. If processing 20 parts per hour is less than planned, it will take four-thirds of the original time.

The total amount of work is constant, and the working efficiency is inversely proportional to the working time, that is, the efficiency ratio is opposite to the time ratio.

Planned time: the first time if = 1: 3/4 = 3: 4.

Planning efficiency: the efficiency of the first if = 4: 3.

The difference is 20, so it is planned to process every hour: 20 ÷ (4-3) × 4 = 80 pieces.

The second processing capacity per hour is 80+ 10 = 90 pieces.

The work efficiency ratio is 8: 9.

Contrary to the efficiency ratio, the time ratio is 9: 8. You left out a number on it. According to that figure, the planned working time can be calculated, and the total workload can be obtained in 80 times.