contestada

9 mountain bikers are on bicycle trip in how many possible ways can they follow each other

Respuesta :

We could have  9 ways to pick the leader x 8 ways to pick the second place rider x 7 ways to pick the third place rider, etc.

So

9 x 8 x 7 x .....x  3 x 2 x 1  = 9!  = 362880  ways to arrange them


ok one way is slot method
9 slots
1st slot-9 possible people
2nd slot- 8 people (1 went to 1st slot
3rd slot-7
4th- 6
5th-  5
6th- 4
7th- 3
8th-2
9th-1

so multiply them
9*8*7*6*5*4*3*2*1= 362880

362,880 ways