Answer:
10%
Step-by-step explanation:
the sun gives energy to the grass (to make it easier to understand, say the sun gives 100un of energy to the plants)
from there, the rabbit eats the grass( 10% of 100 is 10, so the rabbit gets 10un of energy)
and the, a lion eats the rabbit (10% of 10 is 1, so the lion gets 1 un of energy)
every single time a predator consumes prey, it only gets 10% of what the prey gets from its prey.
Hope this helps :)