Arranging of books is an illustration of permutation and combination
There are 24 different possible arrangements she can make
<h3>How to calculate the number of arrangement</h3>
The number of books is given as:
n = 4
Take the factorial of both sides
n! = 4!
Evaluate
n! = 4 * 3 * 2 * 1
n! = 24
Hence, there are 24 different possible arrangements she can make
Read more about permutation and combination at:
brainly.com/question/1216161
15, 18, 21
i don't know the other one, sorry
I think they both go into 10,000 bases of the calculations from the calculator on my phone
Answer:
i think its 10
Step-by-step explanation:
4 6 8 10 15 20 21