Tuna eat sardines and other small fish. Suppose the consumption efficiency of tuna is 40%, the assimilation efficiency is 30%, and the production efficiency is 20%. If tuna eat 1,500 kg of sardines and other small fish, how much will be used to produce tuna biomass?

90 kg. will be used to produce biomass

Explanation:

All we need to do is multiply how much sardines and other small fish every tuna eats, times the tuna's assimilation efficiency (30%) and again multiply times the production efficiency (20%):

tuna's biomass production = 1,500 kg x 30% x 20%

tuna's biomass production = 90 kg