#### Work

The amount of work W, accomplished in time T, depends on the rate R, at which the work is done. This relationship is described by the equation:

W = RT

The amount of work is often one completed job, so usually W = 1.

The time T is how long it takes to complete the entire job.

The rate R is the job divided by time.

Rate = 1 job/time to do 1 job or jobs done/time

#### Rates

A work-rate sounds like a speed, but the unit is a job done, not a distance covered.

There are many work-rates in everyday life.

She types 60 words per minute.

The repairman makes 6 service calls per day.

The hen lays 5 eggs per week.

In the formula, you need to use the unit rate.

*examples of unit rates*

It takes 1 tractor 10 hours to plow 1 field, so the rate for the tractor is 1/10 of a field per hour.

1/tractors × hours = 1/1 tractors × 10 hours = 1/10

It takes x tractors 1 hours to plow 1 field, so the rate for the tractor is 1/x of a field per hour.

1/tractors × hours = 1/x tractors × 1 hour = 1/x

It takes x tractors 4 hours to plow 1 field, so the rate for the tractor is 1/4x of a field per hour.

1/tractors × hours = 1/x tractors × 4 hours = 1/4x

It takes x tractors y hours to plow 1 field, so the rate for the tractor is 1/xy of a field per hour.

1/tractors × hours = 1/x tractors × y hours = 1/xy