Calculating rates

Last updated: 20 May 2008

The rate is the speed with which something occurs. We can calculate the rate by dividing the amount by the time taken so

Rate = `text{Amount} / text{Time}`

You should be able to see that this the same as saying

Widget production example

A machine produces 200 widgets in 10 seconds. What is the rate that it produces widgets at?

Rate = `text{Amount} / text{time} = (200 text{ widgets})/(10 text{ seconds})` = 20 widgets per second

Swimming pool example

A 30,000 gallon swimming pool is filled up at a rate of 600 gallons per hour. How long does it take to fill?

Time = `text{Amount} / text{Rate} = (30,000 text{ gallons})/(600 text{ gallons per hour})` = 50 hours

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