When the doctor is finished, he extensively washes his hands and uses a lot of paper to dry his hands.
When he walks out, he tells the others: "My parents taught me to be clean" and leaves.
When the economist finishes, he washes his fingertips and dries his hands with only one sheet of paper.
When he walks out, he tells the others: "My parents taught me not to waste" and leaves.
When the farmer walks out, he doesn't washes his hands at all.
He tells the others:
Spoiler:
