If biomass of autotrophs is 100 kg, the biomass of secondary consumers will be

The ecological 10% rule states that only about 10% of energy is transferred from one trophic level to the next. Autotrophs (producers) = 100 kg. Primary consumers (herbivores) = 10 kg (10% of 100). Secondary consumers (carnivores that eat herbivores) = 1 kg (10% of 10). However, secondary consumers that eat primary consumers would be at the third trophic level, receiving 10% of 10 kg = 1 kg. But the question asks for secondary consumers directly consuming primary consumers, which would be 10% of the producer biomass.