Two identical buckets C and D contained some water. Bucket C was ¹₆ filled and Bucket D was ¹₇ filled. The ratio of the total mass of Bucket C and the water in it to the total mass of Bucket D and the water in it was 9 : 8. The total mass of the two buckets and the water they contained was 1870 g. What is the mass of an empty bucket?
Mass of Bucket C and the water inside = 9 u
Mass of Bucket D and the water inside = 8 u

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

17 u = 1870

1 u = 1870 ÷ 17 = 110

Mass of Bucket C and the water in it more than mass of Bucket D and the water in it 
= 9 u - 8 u
= 1 u

Fraction of the water that Bucket C had more than Bucket D 
= ¹₆ - ¹₇
= ⁷₄₂ - ⁶₄₂
= ¹₄₂ 

¹₄₂ of the water capacity → 1 u
⁶₄₂ of the water capacity → 6 x 1 u = 6 u

Mass of an empty bucket
= 8 u - 6 u
= 2 u
= 2 x 110
= 220 g

Answer(s): 220 g