Box G and Box H are identical. ⁷₈ of Box G and ³₇ of Box H are filled with sand. The mass of Box H with its contents is ⁹₁₀ the mass of Box G with its contents. The total mass of the two boxes with their contents is 475 kg. Find the mass of an empty box.
Mass of Box G and its contents = 10 u
Mass of Box H and its contents = 9 u

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

19 u = 475 

1 u = 475 ÷ 19 = 25

Mass of Box G with its concents more than mass of Box H with its contents
= 10 u - 9 u
= 1 u
= 1 x 25
= 25 kg

Fraction of the sand that Box G had more than Box H
= ⁷₈ - ³₇
= ⁴⁹₅₆ - ²⁴₅₆
= ²⁵₅₆

²⁵₅₆ of the capacity of sand in a box → 25
¹₅₆ of the capacity of sand in a box → 25 ÷ 25 = 1
²⁴₅₆ of the capacity of sand in a box → 24 x 1 = 24 

Mass of the sand and Box H
= 9 u
= 9 x 25
= 225 kg

Mass of the empty box
= 225 - 24
= 201 kg

Answer(s): 201 kg