A friend told me about his student days:
“We had such a subject as geodesy. One of the coursework required the construction of geodesic curves on the rear points and the use of a special line.
For me, this work was not difficult, a maximum of half an hour. But here is why some girls didn’t give it. And I didn’t like to fuck, well, I didn’t get carefully. In general, an exchange was agreed: I do geodesy, and in exchange I draw the facade of the building.
Although I was happy, I felt a bite of conscience. I said a simple job, a maximum of half an hour, change it to a difficult one, with which the girl will argue a day, or even two.
I bring a ready-made plan to the girls, I go into their block (these are two rooms with a bathroom and a corridor) and suddenly I hear: "Here I have changed fine, I have drawn the facade in twenty minutes, and he has a whole day of geodesy."
So the exchange was fair :)