In this task, you are given a question and an answer, you would be asked to create the sentence based on the Question-Answer provided. It should be contained within the Question-Answer provided.

[Q]: Question: What equals the output power divided by the input power? Answer: efficiency
[A]: Efficiency equals the output power divided by the input power.

[Q]: Question: What type of energy is useful to humans because it's ease of transport and conversion to other forms of energy? Answer: electrical
[A]: Electrical type of energy is useful to humans because it's ease of transport and conversion to other forms of energy.

[Q]: Question: Lichens are not a single organism, but rather an example of a what? Answer: mutualism
[A]:
Lichens are not a single organism, but rather an example of a mutualism.