Question

The lifeguards at the beach post information of surfers by placing 3 flags, one above the other, on a flag pole. If there are 7 different flags available, how many possible signals can be flown?​

Answer 1

Answer:  210

Step-by-step explanation:

1st Flag    and     2nd Flag      and      3rd Flag

7 choices   x      6 choices        x       5 choices      =    210

Using the formula: $\dfrac{7!}{(7-3)!}=\dfrac{7\times 6\times 5\times 4!}{4!}=7\times 6\times 5=\large\boxed{210}$