Martha can rake the leaves in her yard in 5 hours. Her brother can do the job in 2 hours. How long will it take them to do the job working together?

Question

Quizplus · Accepted Answer

Working together, Martha and her brother can complete $\frac{1}{5} + \frac{1}{2} = \frac{2}{10} + \frac{5}{10} = \frac{7}{10}$ of the job per hour. Therefore, it will take them $\frac{10}{7}$ hours to complete the job, which simplifies to $1 \frac{3}{7}$ hours.

Martha Can Rake the Leaves in Her Yard in 5 110\frac{1}{10}101​

Martha Can Rake the Leaves in Her Yard in 5 $\frac{1}{10}$