If three men can chop down three trees in three hours, how many men will it take to chop down six trees in six hours?

Why this works

This riddle plays with the relationship between men, trees, and time. Each man can chop down one tree in three hours, meaning that in six hours, one man can cut down two trees. Therefore, if three men work together, they can collectively chop down six trees in the same six-hour period, as three men can cut down two trees each in that time (2 trees per man multiplied by 3 men gives you 6 trees). The trick lies in realizing that the number of men remains constant regardless of the increased number of trees, as the time allotted allows for the same work rate.