There are 10 000 small screws. They are to be placed in packets of 50. Manual labor is banned.What are the ways that can be used.

Method 1:Electromagnet
Adjust the voltage(resistance) of the electromagnet to pick up the amount og screws that you want.

Disadvantages: Even if you adjust the voltage(resistance) it will still pick up the screws. The screws are magnetic and will be attracted to any magnets.



Method 2:Weighing machine
Place 50 screws on top of the weighing machine.Take down the weight of it. Then, just pick up any amount of screws and placed it on weighing machine. If the reading is more than the first reading,take away some screws. If it is too light, add some screws until the first reading is about the same.

Disadvantages:Time consuming