Answer:
Step-by-step explanation:
Combinatorial explanation:
The n balls have to be arranged in n positions and the only distinction is where are the black and where white balls are.
We can choose the position of black balls in 
ways, therefore, white ones are on the remaining positions.
Using binomial we can have explanation written below:
The balls can be arranged in n! possible permutations.
To be precise one particular arrangement includes 
permutations. Since r black balls can be permuted in r! ways and white balls in (n-r)! different orders.
So basically it yields,
permutations.
So the actual amount is,
Answer:
18,75
Step-by-step explanation:
A square has 4 sides, and each one of them are equal, so 75 divided by 4 its equal to 18,75
Answer:
from what we're given on the drawing, ac and pt are congruent
and from the question format, ab is equal to pq, ac is equal to pr
Answer: 4.77
Step-by-step explanation:
40.68-2.52=38.16/8=4.77
