The process shows recycling of carbon in the carbon cycle. This is because carbon from living organisms is cycled to non living organisms. When plants and animals die and are buried deep in the ground, they are then slowly converted to fossil fuels which contain organic hydrocarbon compounds including petrol, kerosene and other compounds. Then the fossils are used in the industries and undergoes combustion releasing carbon iv oxide which is then released to the atmosphere and used by the plants and animals. The process starts once again.
In an hour there are 60 minutes to find the unit rate of problems per minute you divide 60/24 and get 2.5 multiply 2.5 by 72 get 180 in minutes that is 3 hours