Efficiency can be expressed in terms of the desired divided by the required .

Efficiency is a measure of how effectively a system converts inputs into outputs. It can be expressed as a ratio of the desired output to the required input. Here's a step-by-step explanation:

1. Identify the Desired Output: This is what you want the system to produce. It could be a physical product, a service, or any other result of a process.

2. Identify the Required Input: This is what you need to put into the system to get the desired output. It could be raw materials, energy, time, or any other resource.

3. Calculate the Ratio: Divide the desired output by the required input. This gives you a measure of the system's efficiency.

For example, if a car travels 60 miles on 2 gallons of gas, the efficiency of the car would be 30 miles per gallon. This is because the desired output (distance traveled) is 60 miles and the required input (gas consumed) is 2 gallons. So, 60 miles divided by 2 gallons equals 30 miles per gallon.