Waec Model Questions Vol1 2021 Agricultural Science Question 37

A fish farm starts a breeding programme with 100 breeding pairs. Each pair produces 2,000 eggs. Fertilisation success is 85 % and hatchability of fertilised eggs is 90 %. Survival from hatch to fingerling after the first month is 70 % and survival from fingerling to market size is 80 %. At the end of the first harvest the farmer retains 30 % of the market‑size fish as broodstock; each retained fish weighs 0.2 kg at the time of retention, while the remaining fish are sold at 0.6 kg each. The retained fish are then used as breeding pairs for a second cycle (two fish per pair). All reproductive parameters are identical for the second cycle. What is the total weight (in kilograms) of fish sold after the two successive harvests?