Question 48480
1 4 different red flags:

first flag: 4 possibles
second flag: 3 possibles (since one has been chosen as the first flag)
third flag: 2 possibilities
fourth flag: 1 possible flag.


Total: 4*3*2*1 --> 24 possible ways


2. 2 different red flags (r and R) and 2 identical white flags (W and W)


Permutations are, in order:
rRWW
rWRW
rWWR

RrWW
RWrW
RWWr

WWrR
WWRr
WrRW
WRrW
WrWR
WRWr


so answer is 12. Now algebraically we get this by starting with the 24 as the answer for 4 different flags and then dividing by 2! since we have 2 identical flags (the white ones):


24/2!
24/2
12


Hope this is clear.


jon.