Solve.
-A painter can finish painting a house in 8 hours. Her assistant takes 10 hours to finish the same job. How long would it take for them to complete the job if they were working together?
A) $\frac { 9 } { 40 } \mathrm { hr }$
B) $9 \mathrm { hr }$
C) $7 \mathrm { hr }$
D) $4 \frac { 4 } { 9 } \mathrm { hr }$

Question

Quizplus · Accepted Answer

Working together, the painter and her assistant can complete $\frac{1}{8} + \frac{1}{10} = \frac{5}{40} + \frac{4}{40} = \frac{9}{40}$ of the job per hour. To complete the job, it would take them $\frac{1}{\frac{9}{40}} = \frac{40}{9}$ hours, which simplifies to $4 \frac{4}{9}$ hours.

Solve -A Painter Can Finish Painting a House in 8 940hr\frac { 9 } { 40 } \mathrm { hr }409​hr

Solve
-A Painter Can Finish Painting a House in 8 $\frac { 9 } { 40 } \mathrm { hr }$