Signals
The king has 10 (different) colored flags that he uses to send coded messages to his general in the field. For example, red-blue-green might mean “attack at dawn” and blue-green-red may mean “retreat.” He sends the message by arranging three of the flags atop the castle wall.
The maximum number of such coded messages is _______.
(Give your answer as a whole number.)
6 answers
10! /(10-3)! = 10!/7! = 10*9*8
Google "permutations" by the way.
I got 518400 but it's considered wrong.
90*8 - 720
10*9*8 = 720, not 518400
Hmmm. 518400 = (10*9*8)^2
Why did you use that?
Why did you use that?
1 answer