Two identical containers E and F contained some water. Container E was ¹₃ filled and Container F was ¹₄ filled. The ratio of the total mass of Container E and the water in it to the total mass of Container F and the water in it was 6 : 5. The total mass of the two containers and the water they contained was 1430 g. What is the mass of an empty container?
Mass of Container E and the water inside = 6 u
Mass of Container F and the water inside = 5 u

Total mass of the two containers and the water inside them
= 6 u + 5 u
= 11 u

11 u = 1430

1 u = 1430 ÷ 11 = 130

Mass of Container E and the water in it more than mass of Container F and the water in it 
= 6 u - 5 u
= 1 u

Fraction of the water that Container E had more than Container F 
= ¹₃ - ¹₄
= ⁴₁₂ - ³₁₂
= ¹₁₂ 

¹₁₂ of the water capacity → 1 u
³₁₂ of the water capacity → 3 x 1 u = 3 u

Mass of an empty container
= 5 u - 3 u
= 2 u
= 2 x 130
= 260 g

Answer(s): 260 g