The mass of an empty container is 3/10kg. When the container is half filled with water, the mass becomes 1 1/10kg. What is the mass of the container when it is completely filled with water

1.9 kg

Step-by-step explanation:

Empty container: 3/10 kg = 0.3 kg

Container half filled: 1 1/10 kg = 1.1 kg

Mass of water that fills it halfway: 1.1 kg - 0.3 kg = 0.8 kg

Mass of water that fills it completely: 2 * 0.8 kg = 1.6 kg

Mass of container completely filled with water: 0.3 kg + 1.6 kg = 1.9 kg