Box G and Box H are identical. ⁵₆ of Box G and ³₈ of Box H are filled with sand. The mass of Box H with its contents is ⁸₉ the mass of Box G with its contents. The total mass of the two boxes with their contents is 374 kg. Find the mass of an empty box.
Mass of Box G and its contents = 9 u
Mass of Box H and its contents = 8 u

Total mass of the two boxes with their contents
= 9 u + 8 u
= 17 u

17 u = 374 

1 u = 374 ÷ 17 = 22

Mass of Box G with its concents more than mass of Box H with its contents
= 9 u - 8 u
= 1 u
= 1 x 22
= 22 kg

Fraction of the sand that Box G had more than Box H
= ⁵₆ - ³₈
= ²⁰₂₄ - ⁹₂₄
= ¹¹₂₄

¹¹₂₄ of the capacity of sand in a box → 22
¹₂₄ of the capacity of sand in a box → 22 ÷ 11 = 2
⁹₂₄ of the capacity of sand in a box → 9 x 2 = 18 

Mass of the sand and Box H
= 8 u
= 8 x 22
= 176 kg

Mass of the empty box
= 176 - 18
= 158 kg

Answer(s): 158 kg