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.
Roberto paints 1/6 of a room in 1 hour.
Julio paints1/8 of a room in 1 hour.
Working together, they paint (1/6 + 1/8) = (4/24 + 3/24) = 7/24 room per hour.
The reciprocal unit rate is 24/7 hour per room = <em>3-3/7 hours</em> per room.
No, no value for x will result in you getting the same amount of money
I.e. on the first day if x =2 you earn 33. on the second day you would've earned 44. Of course this may be wrong so best to double check
Hello,
The answer to this problem is, C.
4 minus the quotient of a number and 3
Hope this helps!