IKMC 2027 - Grades 7-8 - Self-study SET 13 - Thematic Batch 3 Question 25

Ms May has a two-pan balance and weights of 2 kg and 3 kg. Starting with 13 kg of salt, what is the fewest weighings needed to obtain exactly 7 kg of salt? Salt may be poured gradually onto the pans.

Editorial model: Salt is placed directly on the pans, or container masses are tared out.