Answer:
Step-by-step explanation:
To find the number of different ways she can stack 3 of them in a tower, we need to use the formula:
[tex]_{n}P_{k}=\dfrac{n!}{(n-k)!}[/tex]
n = 4
k = 3
[tex]_{n}P_{k}=\dfrac{4!}{(4-3)!}[/tex]
[tex]_{n}P_{k}=\dfrac{4!}{1!}[/tex]
[tex]_{n}P_{k}=\dfrac{4*3*2*1!}{(1)!}[/tex]
[tex]_{n}P_{k}=\dfrac{4*3*2*1!}{1}[/tex]
[tex]_{n}P_{k}=\dfrac{24}{1}[/tex]
