Answer:
t=72 minutes
Step-by-step explanation:
If it takes Lisa 3 hours to mow the lawn, then she mows 13 of the lawn per hour. Barb takes 2 hours to do it alone so she completes 12 of the lawn each hour. Working together, they mow the lawn in some time t. This can be written as
[tex]\frac{1}{3}[/tex]+[tex]\frac{1}{2}[/tex]=[tex]\frac{1}{t}[/tex]
Multiply each side by the least common denominator, 6t.
6t([tex]\frac{1}{3}[/tex]+[tex]\frac{1}{2}[/tex])=6t([tex]\frac{1}{t}[/tex])
Simplify and solve.
2t+3t=6
We can multiply the fraction by 60 to convert the fraction of an hour to minutes.
t=[tex]\frac{6}{5}[/tex] (60 minutes)
To mow the lawn, it takes the two working together
t=72 minutes.
