Question

Robin can clean 72 rooms in 6 daysHow many rooms can Robin clean in 9 days?A. 64B.108C. 648 D. 9

Answer 1

72 rooms are proportional to 6 days. To find how many rooms are proportional to 9 days, we can use the next proportion:

`\frac{72\text{ rooms}}{x\text{ rooms}}=\frac{6\text{ days}}{9\text{ days}}`

Solving for x,

`\begin{gathered} 72\cdot9=6\cdot x \\ (648)/(6)=x \\ 108\text{ rooms=x} \end{gathered}`

Robin can clean 108 rooms in 9 days