How can you use a balance scale without weights to divide 24 kg of nails into two parts - 9 and 15 kg?

#
Try to weigh out 12 kg first, then -6 kg, and then -3 kg.

## Solution

Weigh out 12 kg of nails and set them aside. From the remaining 12 kg, weigh out 6 kg and set them aside in a different place. From the remaining 6 kg, weigh out 3 kg and combine them with the 6 kg that were set aside. We get the desired 9 kg of nails.

## Answer

Weigh out 12 kg; from them, weigh out 6 kg and set them aside; from the remaining 6 kg, weigh out 3 kg and combine them with the 6 kg that were set aside.