An amusement park has 13 roller coasters. In how many ways can you choose 4 of the roller coasters to ride during your visit to the park?
1 Answer
Sep 30, 2016
Assuming you want to choose 4 different roller coasters.
Explanation:
Then for the first you choose from all 13, for the second from the remaining 12, etc.
This gives you
But then, if the order in which you ride them doesn't matter, you have to divide this by the number of possible orders in which to ride your 4 choices:
Summary :
For choosing 4 rides out of 13, when order is unimportant:
Note: If you use a GC, the function