Harvesting a piece of wheat, originally planned for 20 people, 12 hours, harvested for 4 hours, the weather suddenly changed, and the rest had to be harvested for two hours. I asked how many people wo

Harvesting a piece of wheat, originally planned for 20 people, 12 hours, harvested for 4 hours, the weather suddenly changed, and the rest had to be harvested for two hours. I asked how many people would be added. Step by step:

It can be seen from the title "12 hours, 4 hours" that 1/3 is collected.

We still need to collect 2/3.

One person charges 1/( 12*20) an hour.

According to "the rest should be collected within two hours", it is known that 1/3 should be collected every hour.

Add (1/3)/(1/(12 * 20)).

One-step completion

Solution: One person is necessary.

20* 12=20*4+(20+a)*2

Available a=60

The answer is 60 people