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.
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
Wow, look at you go! How did you do that economyst?!
Its just logic. Plus it helps if you have seen the problem before.
To divide the salt among the spoons, follow these steps:
1. Start by transferring 4 tsps of salt from Spoon A to Spoon B. This will leave Spoon A with 8 - 4 = 4 tsps of salt and Spoon B with 0 + 4 = 4 tsps of salt.
2. Next, transfer 3 tsps of salt from Spoon B to Spoon C. This will leave Spoon B with 4 - 3 = 1 tsp of salt and Spoon C with 0 + 3 = 3 tsps of salt.
3. Finally, transfer the remaining 1 tsp of salt from Spoon B back to Spoon A. This will leave Spoon A with 4 + 1 = 5 tsps of salt and Spoon B empty.
By following these steps, Spoon A will have exactly 4 tsps of salt, Spoon B will be empty, and Spoon C will be empty as well.