Igcse Model Questions Vol1 2019 Biology Question 21

Grass in a savanna produces 20\,000\,kJ of chemical energy per day. Two herbivore species feed on the grass. Species A receives \(10\%\) of the grass energy and each individual of species A requires 150\,kJ per day. Species B receives \(6\%\) of the grass energy and each individual of species B requires 300\,kJ per day. The remaining herbivore energy that is actually consumed (i.e., after accounting for the integer numbers of individuals) is available to a carnivore species (hawks). Hawks obtain \(25\%\) of the total energy consumed by the two herbivore species and each hawk needs 600\,kJ per day. Assuming the herbivore populations are as large as possible given the energy they receive, what is the maximum number of hawks that can be sustained?