Question

Max can mow a lawn in 45 minutes. Jan takes twice as long to mow the same lawn. If they work together, how long will it take them to mow the lawn?

Answer 1

Look at each worker's rate of work. I prefer to convert to hours.

Max does the job in 45 minutes or 0.75 hour
His rate is 1/0.75 job/hour

Jan does the job in 90 minutes or 1.5 hours.
Her rate is 1/1.5 job per hour

When you add these rates, you get the total rate, x.

\(\dfrac{1}{0.75} + \dfrac{1}{1.5} = \dfrac{1}{x} \)

Solve for x.