Answer:
see below for more steps
Step-by-step explanation:
If a consumer loses 70% of the 2000J energy in their food as waste heat, that would be 70/1002000 = 1400 J
And if 20% in their waste products, that would be 20/1002000 = 400 J
So the total amount of energy lost as waste heat and in waste products is 1400 J + 400 J = 1800 J