AWOL part 7

Was taking the train home when I overhead this conversation between two Dunman High students.

Student No.1: Hey I'm gonna ask you a riddle...

Student No.1: If Farmer A sells potatoes and Farmer B sells tomatos, then what does Farmer C sells?

(Student No.2 attempted some answers but all were incorrect.)

Student No.2: I give up, so what does he sell?

Student No.1: He sells medicine.

What can I say? The simple joys of being a kid. Makes me kinda miss my secondary school days.