After providing one eraser to each of the 4 kids, there are 3 erasers remaining. The distribution can be done in either 2, 1, or 1, 1, 1 manner (no kid can receive 4 erasers).
There are a total of 4P2+4C3, which equals 16 ways of distributing the erasers.
In how many ways can 5 identical balls be distributed into 3 distinct boxes?
What is the value of x if:
2x · 3x+1 = 3888
In how many ways can 6 people be seated around a circular table?