A container filled with 10 king melons has a mass of 9.08 kg. The same container when filled with 3 pomegranates has a mass of 0.61 kg. The mass of 1 king melon is eight 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

9.08 kg = 9080 g
0.61 kg = 610 g

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

1 container + 3 pomegranates = 610
1 container + 3 u = 610 --- (1)

1 king melon = 8 u
10 king melons = 10 x 8 u = 80 u

1 container + 10 king melons = 9080
1 container + 80 u = 9080 --- (2)

(2) - (1)
80 u - 3 u = 9080 - 610
77 u = 8470

1 u = 8470 ÷ 77 = 110

3 u = 3 x 110 = 330

From (1):
1 container + 3 u = 610
1 container + 330 = 610
 
1 container = 610 - 330 = 280

Mass of 1 container = 280 g

Answer(s): 280 g