A container filled with 9 jackfruits has a mass of 5.3 kg. The same container when filled with 3 pomegranates has a mass of 0.68 kg. The mass of 1 jackfruit is four 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

5.3 kg = 5300 g
0.68 kg = 680 g

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

1 container + 3 pomegranates = 680
1 container + 3 u = 680 --- (1)

1 jackfruit = 4 u
9 jackfruits = 9 x 4 u = 36 u

1 container + 9 jackfruits = 5300
1 container + 36 u = 5300 --- (2)

(2) - (1)
36 u - 3 u = 5300 - 680
33 u = 4620

1 u = 4620 ÷ 33 = 140

3 u = 3 x 140 = 420

From (1):
1 container + 3 u = 680
1 container + 420 = 680
 
1 container = 680 - 420 = 260

Mass of 1 container = 260 g

Answer(s): 260 g