Box H and Box J are identical. ³₄ of Box H and ³₅ of Box J are filled with sand. The mass of Box J with its contents is ⁹₁₀ the mass of Box H with its contents. The total mass of the two boxes with their contents is 228 kg. Find the mass of an empty box.
Mass of Box H and its contents = 10 u
Mass of Box J and its contents = 9 u

Total mass of the two boxes with their contents
= 10 u + 9 u
= 19 u

19 u = 228 

1 u = 228 ÷ 19 = 12

Mass of Box H with its concents more than mass of Box J with its contents
= 10 u - 9 u
= 1 u
= 1 x 12
= 12 kg

Fraction of the sand that Box H had more than Box J
= ³₄ - ³₅
= ¹⁵₂₀ - ¹²₂₀
= ³₂₀

³₂₀ of the capacity of sand in a box → 12
¹₂₀ of the capacity of sand in a box → 12 ÷ 3 = 4
¹²₂₀ of the capacity of sand in a box → 12 x 4 = 48 

Mass of the sand and Box J
= 9 u
= 9 x 12
= 108 kg

Mass of the empty box
= 108 - 48
= 60 kg

Answer(s): 60 kg