You have 3 measuring spoons. Spoon A is filled with 8 tsps of salt. Spoon B and C are both empty; Spoon B can hold 5 tsps and Spoon C can hold 3 tsps. Divide the salt among the spoons so that spoon A and spoon B each have exactly 4 tsps of salt and spoon c is empty.

Answer 1

1) fill C from A -- A=5, B=0, C=3
2) fill B from C -- A=5, B=3, C=0
3) fill C from A -- A=2, B=3, C=3
4) fill B from C -- A=2, B=5, C=1
5) fill A from B -- A=7, B=0, C=1
6) fill B from C -- A=7, B=1, C=0
7) fill C from A -- A=4, B=1, C=3
8) fill B from C -- A=4, B=4, C=0
tada

Answer 2

Wow, look at you go! How did you do that economyst?!

Answer 3

Its just logic. Plus it helps if you have seen the problem before.