1. Everyone except half a day+half a day is a big piece that has just been mowed. It is known that it takes 1.5 days if only half of the people are used to weed that large piece of grass;

2. Small plots are 1/2 of large plots, from 1. So it takes 0.75 days for half of people to remove the plot;

3. According to the meaning of the question, half of the people have to weed for 0.25 days in addition to weeding on a small piece of land;

4. Half of people weed for 0.25 days, while one person needs 1 day, so it can be seen that the number of half people is: 4.

5. So, there are 8 people in this group.

It is too simple to use a few unknowns to make equations.

There are x people in a group, and the amount of weeding per person per day is A, so there are:

1. The mass of grass =0.5aX+0.5 x(0.5aX) *** The small x represents the multiplication sign;

2. The amount of grass in the plot = 0.5 x (0.5 ax)+a.

Above 1. The formula is twice that of 2. The solution is X=8.