A container filled with 12 honeydews has a mass of 8.15 kg. The same container when filled with 7 mangoes has a mass of 1 kg. The mass of 1 honeydew is six times the mass of 1 mango. Find the mass of the container when it is empty. Express the answer in g.
1 kg = 1000 g

8.15 kg = 8150 g
1 kg = 1000 g

1 mango = 1 u
7 mangoes = 7 x 1 u = 7 u

1 container + 7 mangoes = 1000
1 container + 7 u = 1000 --- (1)

1 honeydew = 6 u
12 honeydews = 12 x 6 u = 72 u

1 container + 12 honeydews = 8150
1 container + 72 u = 8150 --- (2)

(2) - (1)
72 u - 7 u = 8150 - 1000
65 u = 7150

1 u = 7150 ÷ 65 = 110

7 u = 7 x 110 = 770

From (1):
1 container + 7 u = 1000
1 container + 770 = 1000
 
1 container = 1000 - 770 = 230

Mass of 1 container = 230 g

Answer(s): 230 g