Gormands - Colegiul Ortodox "Mitropolitul Nicolae Colan" (Cluj-Roumanie)

In order to launch a new range of tarts, it is first necessary to conduct tests. Let’s assume, for
simplicity, that there are 4 tarts to test : apple, strawberry, cherry, and apricot.We also have 4
testers : Pierre, Julie, Paul, and Emma.In order for the test to be as efficient as possible, we also
have 4 different rooms to conduct the tests.
— Is it possible to organize the tests so that each person tests each tart only once, this way there
will be, in each room, each tester and each tart only once ?
— Generalize from 4 to n, where n is any number (particularly consider n = 6).