First of all, what is the most reasonable: the total amount of earth moved every day = the total amount of earth dug every day, so the equation is listed according to this equation.

Suppose there are x people digging the earth, then the person who lifts the earth is 48-x people.

According to the meaning of the question:

5x=(48-x)*3

5x= 144-3x

8x= 144

x= 18

Therefore, it is most reasonable to have 18 people digging and 30 people moving soil.