Question

A carpenter spend his 40-hour workweek as follows: 1/4 of his ordering materials; 1/2 of his time doing the wooodwork; and 1/8 of his time talking to customers. The rest of his time devoted to cleanup. What is the approximately percentage of time the carpenter spend doing cleanup?

Answer 1

Step-by-step explanation

The forty hours of the workweek of the carpenter are distributed as follows:

Then, the time that the carpenter spends cleaning up is (what remains from the 40 hours after subtracting the time he spends in the other activities):

`40h-10h-20h-5h=5h\text{.}`

The question now is, what percentage does 5h represent in 40h? We need to use the percentage formula:

`\begin{gathered} 5=(\%)/(100)\cdot40.\leftarrow\begin{cases}\%=\text{ Percentage that 5 represents in 40}\end{cases} \\ \\ \end{gathered}`

Solving this equation, we get

`\begin{gathered} 5=(\%)/(100)\cdot40, \\ \\ 5=(\%\cdot40)/(100), \\ \\ 100\cdot5=\%\cdot40, \\ \\ 500=\%\cdot40, \\ \\ (500)/(40)=\%, \\ \\ \%=(500)/(40), \\ \\ \%=12.5. \end{gathered}`Answer

The percentage of time that the carpenter spends cleaning up is 12.5%.