A container filled with 13 durians has a mass of 8.82 kg. The same container when filled with 8 mangoes has a mass of 1.12 kg. The mass of 1 durian 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

8.82 kg = 8820 g
1.12 kg = 1120 g

1 mango = 1 u
8 mangoes = 8 x 1 u = 8 u

1 container + 8 mangoes = 1120
1 container + 8 u = 1120 --- (1)

1 durian = 6 u
13 durians = 13 x 6 u = 78 u

1 container + 13 durians = 8820
1 container + 78 u = 8820 --- (2)

(2) - (1)
78 u - 8 u = 8820 - 1120
70 u = 7700

1 u = 7700 ÷ 70 = 110

8 u = 8 x 110 = 880

From (1):
1 container + 8 u = 1120
1 container + 880 = 1120
 
1 container = 1120 - 880 = 240

Mass of 1 container = 240 g

Answer(s): 240 g