There is a balance with two discs and 1 kg weight. How to take 2.5 kgof rice from a 13 kg bucket after two times of balancing?

There is a balance with two discs and 1 kg weight. How to take 2.5 kg
of rice from a 13 kg bucket after two times of balancing?
Giải nhanh giúp mình, chỉ cần phép tính và đáp số !