Neco Model Questions Vol1 2019 Biology Question 16

In a simple three‑trophic‑level ecosystem, grass produces (5,000\,\text{kg}\) of biomass per year. Herbivores (rabbits) convert \(10\%\) of the grass biomass into their own biomass. A disease reduces the rabbit biomass by \(20\%\) each year before they are consumed by carnivores (foxes). Foxes convert \(15\%\) of the surviving rabbit biomass into fox biomass. Additionally, foxes suffer a natural mortality loss of \(10\%\) of their biomass each year; the lost biomass is recycled to the rabbit level with a conversion efficiency of \(10\%\) and the resulting rabbit biomass is again available to foxes with the same \(15\%\) efficiency. Assuming no other inputs or losses, what is the net fox biomass (in kg) present after one year?