What is flow the energy to a third -level consumer if the producer provides 1500 calories of energy to the first-level consumer?

Only about 10% is passed from level to level. In this case it is 10% of 1500 calories or 150 calories. This the reason why there has to be many, many producers and why there are only a few consumers. And why you will only see a few eagles or wolves at the very top of the pyramid.