Level 3
Ben had some flour. He used the same amount of flour each day. By the end of Day 5, he had 590 g of flour left. At the end of Day 6, he had 540 g of flour left. How much flour did Ben have at first?
Level 3
A container filled with 4 identical marbles weighs 1700 g. The same container when filled with 2 identical balls weighs 500 g. The mass of each marble is two times the mass of each ball. What is the mass of the container?