Table unit price: chair unit price = 3: 1.
Total table price: total chair price = 3: 1.
Number of groups: 180 ÷ (3+ 1) = 45 (group)
(17+3) ÷ (1-5/9) = 45 (person)
Pour water/bottle: 5-3 = 2 (bottle)
Corresponding weight: 3× 5 = 15 (kg)
Each bottle: 15 ÷ 2 = 7.5 (kg)