The mass of the container is 5.81 kilograms when completely filled with sugar. The mass of the container is 3.8 kilograms when 3 / 8 of the sugar is removed. What is the mass of the empty container



Answer :

removed sugar is 3/8 and it is 5.81-3.8=2.01 kg
so 3/8 is 2.01 kg
full mass of sugar is 2.01:3*8=5.6 kg 
so the mass of container is 5.81-5.6=0.21 kg
Answer: the mass of empty container is 0.21kg