Question

If it takes 30 minutes to clean off 6 desks, how many hours will it take to clean off 126 desks at the same rate?

Answer 1

Given that:

It took 30 minutes to clean off 6 desks, let us now solve the amount of desks to clean off in 1 hour.

Therefore,

`30mins\rightarrow hr=(30)/(60)hr=(1)/(2)hr`

Thus,

`\begin{gathered} (1)/(2)hr=6desks \\ \therefore1hr=(6desks)/((1)/(2))=6/(1)/(2)=6*(2)/(1)=12desks \end{gathered}`

Therefore, it took him/her 1 hour to clean off 12desks.

Hence, the amount of hours it will take to clean off 126 desks will be

`(126desks)/(12desk)*1hr=10(1)/(2)hours`

Therefore, the answer is

`10(1)/(2)hours`