Question

o vagao de um trem possui seis portas . de quantas maneiras distintas um passageiro pode entra no trem e sair dele por uma porta diferente da que entrou

Answer 1

Solution :-

We can simply solve this mathematical problem using the following process:

using the idea of permutation and combinations, we can determine how many distinct ways there are for a guy to enter the room  by one door and exit it through a different door, as seen below;

= $6_{C}_{2}$ × 2

Since each pair of door can be tallied twice since one door is utilized for entry in the first case and them for exit in the second , the number ( 6c2 ) reflects the potential paired combinations for the room's six doors.

= 6! / ( 4! 2! ) × 2

= 6! / 4!

= 5 × 6

= 30