Question 1142722
10 babies arranced in merit can be arranged in 10! ways.
10! = 3628800 ways.
10! is equal to 10 * 9 * 8 * 7 * 6 * 5 * 4 * 3 * 2 * 1.
do the math and you will get 3628800, as shown above.


2 babies from the group of 10 can be selected in c(10,2) ways.
the general formula for c(n,x) is n! / (x! * (n-x)!).
c(10,2) = 10! / (2! * 8!) = (10 * 9 * 8!) / (2! * 8!) = (10 * 9) / (2 * 1) = 45.


here's some references on factorial.


<a href = "https://www.mathsisfun.com/numbers/factorial.html" target = "_blank">https://www.mathsisfun.com/numbers/factorial.html</a>


here's a reference on combinations and permutations.
combinations are without order.
permutations are with order.


<a href = "https://www.mathsisfun.com/combinatorics/combinations-permutations.html" target = "_blank">https://www.mathsisfun.com/combinatorics/combinations-permutations.html</a>