Probability Question

Question

I am having trouble answering this. Can someone please help?

The king has 11 (different) colored flags that he uses to send coded messages to his general in the field. For example, blue-green-red-white might mean "attack at dawn" and white-red-green-blue may mean "retreat." He sends the message by arranging four of the flags atop the castle wall. How many coded messages can the king sent?

Answer 1

This would be an example of a permutation since order will matter( red,blue is not the same as blue red.

For the first flag he has 11 choices. For the second 10 choices. For the third 9 and 8 for the fourth

So he can send 11 x 10 x 9 x8 different messages

This equals 7290