Old Nuts

Why do this problem?
It's a well known problem but intriguing nevertheless. As the solution shows, it can be solved by just working systematically with the information, thinking about which numbers are divisible by 4 and 3, and testing the possibilities. Modulus arithmetic provides an efficient way to solve the problem.

Possible extension
Solve the generalised problem with $n$ castaways, dividing the pile into nshares, hiding one shareand throwing m coconuts to the monkeys each time.