A container filled with 12 durians has a mass of 15.32 kg. The same container when filled with 7 mangosteens has a mass of 1.46 kg. The mass of 1 durian is seven times the mass of 1 mangosteen. Find the mass of the container when it is empty. Express the answer in g.
1 kg = 1000 g

15.32 kg = 15320 g
1.46 kg = 1460 g

1 mangosteen = 1 u
7 mangosteens = 7 x 1 u = 7 u

1 container + 7 mangosteens = 1460
1 container + 7 u = 1460 --- (1)

1 durian = 7 u
12 durians = 12 x 7 u = 84 u

1 container + 12 durians = 15320
1 container + 84 u = 15320 --- (2)

(2) - (1)
84 u - 7 u = 15320 - 1460
77 u = 13860

1 u = 13860 ÷ 77 = 180

7 u = 7 x 180 = 1260

From (1):
1 container + 7 u = 1460
1 container + 1260 = 1460
 
1 container = 1460 - 1260 = 200

Mass of 1 container = 200 g

Answer(s): 200 g