A container filled with 11 mangoes has a mass of 15.62 kg. The same container when filled with 3 pomegranates has a mass of 0.82 kg. The mass of 1 mango is seven times the mass of 1 pomegranate. Find the mass of the container when it is empty. Express the answer in g.
1 kg = 1000 g

15.62 kg = 15620 g
0.82 kg = 820 g

1 pomegranate = 1 u
3 pomegranates = 3 x 1 u = 3 u

1 container + 3 pomegranates = 820
1 container + 3 u = 820 --- (1)

1 mango = 7 u
11 mangoes = 11 x 7 u = 77 u

1 container + 11 mangoes = 15620
1 container + 77 u = 15620 --- (2)

(2) - (1)
77 u - 3 u = 15620 - 820
74 u = 14800

1 u = 14800 ÷ 74 = 200

3 u = 3 x 200 = 600

From (1):
1 container + 3 u = 820
1 container + 600 = 820
 
1 container = 820 - 600 = 220

Mass of 1 container = 220 g

Answer(s): 220 g