A container filled with 8 king melons has a mass of 4.6 kg. The same container when filled with 7 starfruits has a mass of 0.97 kg. The mass of 1 king melon is five times the mass of 1 starfruit. Find the mass of the container when it is empty. Express the answer in g.
1 kg = 1000 g

4.6 kg = 4600 g
0.97 kg = 970 g

1 starfruit = 1 u
7 starfruits = 7 x 1 u = 7 u

1 container + 7 starfruits = 970
1 container + 7 u = 970 --- (1)

1 king melon = 5 u
8 king melons = 8 x 5 u = 40 u

1 container + 8 king melons = 4600
1 container + 40 u = 4600 --- (2)

(2) - (1)
40 u - 7 u = 4600 - 970
33 u = 3630

1 u = 3630 ÷ 33 = 110

7 u = 7 x 110 = 770

From (1):
1 container + 7 u = 970
1 container + 770 = 970
 
1 container = 970 - 770 = 200

Mass of 1 container = 200 g

Answer(s): 200 g