How many different signals can be made by using at least three different flags if there are 6 different flags from which to select?

Question

How many different signals can be made by using at least three different  flags if there are 6 different flags from which to select?

anonymous · Answer

thanks

anonymous · Answer

nope

anonymous · Answer

because it says "at least 3" not "exactly 3"

lgbasallote · Answer

so how should it be?? :O

anonymous · Answer

so it could be 3, 4, 5, or 6  flags used 
plus, it is not clear if order counts for this one 
i would imagine it would but i could be wrong

lgbasallote · Answer

well that was embarrassing *whistle*

kropot72 · Answer

$$\left(\begin{matrix}6 \ 3\end{matrix}\right)+\left(\begin{matrix}6 \ 4\end{matrix}\right)+\left(\begin{matrix}6 \ 5\end{matrix}\right)+\left(\begin{matrix}6 \ 6\end{matrix}\right)$$

anonymous · Answer

@kropot72  is assuming order does not count in his/her computation

zarkon · Answer

$$\sum_{k=3}^{6} \,_6P_k$$

anonymous · Answer

and i don't know if that is correct or not, but i would assume that say 
Red, Green, Yellow
is different from 
Green, Yellow, Red 
etc

anonymous · Answer

more succinctly put by zarkon, that calculation is the one i wrote above

zarkon · Answer

no

kropot72 · Answer

$$\frac{6!}{3!}+\frac{6!}{2!}+\frac{6!}{1}+\frac{6!}{1}$$
As per @Zarkon

zarkon · Answer

yes

anonymous · Answer

wow was i ever off!