A container filled with 12 mangoes has a mass of 11.59 kg. The same container when filled with 5 mangosteens has a mass of 1.14 kg. The mass of 1 mango is five 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

11.59 kg = 11590 g
1.14 kg = 1140 g

1 mangosteen = 1 u
5 mangosteens = 5 x 1 u = 5 u

1 container + 5 mangosteens = 1140
1 container + 5 u = 1140 --- (1)

1 mango = 5 u
12 mangoes = 12 x 5 u = 60 u

1 container + 12 mangoes = 11590
1 container + 60 u = 11590 --- (2)

(2) - (1)
60 u - 5 u = 11590 - 1140
55 u = 10450

1 u = 10450 ÷ 55 = 190

5 u = 5 x 190 = 950

From (1):
1 container + 5 u = 1140
1 container + 950 = 1140
 
1 container = 1140 - 950 = 190

Mass of 1 container = 190 g

Answer(s): 190 g