Answer:
20
Step-by-step explanation:
Once you give 1 candy to each of the 4 kids, you will have 3 remaining. The number of ways those can be distributed to 4 kids is given by ...
(n+k-1)C(n)
where n is the number of candies, and k is the number of kids. "aCb" is the number of ways a can be taken b at a time:
aCb = a!/(b!(a-b)!)
For n=3 and k=4, this is ...
(3+4-1)C(3) = 6C3 = 6!/(3!·3!) = 20
There are 20 ways to distribute 7 candies to 4 kids so that each kid receives at least one.
