According to the Aluminum Association, every year over 100 billion aluminum cans are produced, and of these, approximately 60% were recycled. Measure the mass of ten aluminum cans, and use an average mass for an aluminum can to estimate the total mass of aluminum cans that was recycled.

Can you explain this problem step by step and give answer in 3 significant figures

An Egyptian pyramid contains approximately 1.60 million stone blocks. The average weight of each block is 2.35 tons. What is the weight of the pyramid in pounds?

a.     A painter uses 4.5 litres of paint to cover a wall with an area of 50 m2. Calculate the average rate of paint coverage in m2/L. b     The painter works for 1.5 hours and then rests for half an hour before completing the painting in another hour. Find the average rate at which the painter paints the wall in m2/h.