Two identical containers T and U contained some water. Container T was ¹₄ filled and Container U was ¹₅ filled. The ratio of the total mass of Container T and the water in it to the total mass of Container U and the water in it was 9 : 8. The total mass of the two containers and the water they contained was 2380 g. What is the mass of an empty container?
Mass of Container T and the water inside = 9 u
Mass of Container U and the water inside = 8 u

Total mass of the two containers and the water inside them
= 9 u + 8 u
= 17 u

17 u = 2380

1 u = 2380 ÷ 17 = 140

Mass of Container T and the water in it more than mass of Container U and the water in it 
= 9 u - 8 u
= 1 u

Fraction of the water that Container T had more than Container U 
= ¹₄ - ¹₅
= ⁵₂₀ - ⁴₂₀
= ¹₂₀ 

¹₂₀ of the water capacity → 1 u
⁴₂₀ of the water capacity → 4 x 1 u = 4 u

Mass of an empty container
= 8 u - 4 u
= 4 u
= 4 x 140
= 560 g

Answer(s): 560 g