LESSON 17 Solving Work Problems
Work problems involve people doing a job. For example, if Frank can cut a
lawn in 2 hours and his younger brother can cut the same lawn in 3 hours,
how long will it take them to cut the grass if they both work together? In
this case, we have two people doing the same job at the same time but at
different rates.
Another type of problem involves pipes filling or draining bodies of water
such as tanks, reservoirs, or swimming pools, at different rates. For example,
if one pipe can fill a large tank in 5 hours, and a smaller pipe can fill the tank
in 3 hours, how long would it take to fill the tank if both pipes are turned on at
the same time? Again, we have two pipes doing the same job at different rates.
The basic principle is that the amount of work done by one person,
machine, or pipe, plus the amount of work done by the second person,
machine, or pipe, is equal to the total amount of work done in a given specific
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