A container filled with 11 jackfruits has a mass of 14.09 kg. The same container when filled with 8 mangoes has a mass of 1.67 kg. The mass of 1 jackfruit is seven 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

14.09 kg = 14090 g
1.67 kg = 1670 g

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

1 container + 8 mangoes = 1670
1 container + 8 u = 1670 --- (1)

1 jackfruit = 7 u
11 jackfruits = 11 x 7 u = 77 u

1 container + 11 jackfruits = 14090
1 container + 77 u = 14090 --- (2)

(2) - (1)
77 u - 8 u = 14090 - 1670
69 u = 12420

1 u = 12420 ÷ 69 = 180

8 u = 8 x 180 = 1440

From (1):
1 container + 8 u = 1670
1 container + 1440 = 1670
 
1 container = 1670 - 1440 = 230

Mass of 1 container = 230 g

Answer(s): 230 g