The answer relies on whether the balls are different or not.
If they are not, which is almost certainly what is intended.
If they are, the perceptive is a bit different. Your
expression gives the likelihood that a particular set of j balls
goes into the last urn and the other n−j balls into the other urns.
But there are (nj) different possible sets of j balls, and each of
them the same probability of being the last insides of the last urn, so the
total probability of completing up with exactly j balls in the last
urn is if the balls are different.
See attached file for the answer.
Answer: He can make 36 different salds
Step-by-step explanation:
Answer:
22.5 cm
Step-by-step explanation:
9 inches=9×2.5 cm =22.5 cm
Answer: x=-3 y=7.
Step-by-step explanation:


Answer:
Step-by-step explanation:
First distribute. -2•x and -2•3
This will give you y-4=-2x+-6
(You could also write it y-4=-2x-6)
Then add 4 to both sides.
y=-2x-2