60.8k views
4 votes
an electrician can wire a house in 12 hours. her assistant takes 18 hours to wire the same house. how long would it take them to wire the house together

User AhmedBM
by
7.3k points

1 Answer

4 votes

Solution

The electrician can wire 1/12 of a house per hour.

an apprentice can do 1/18 of a house per hour.

=>x/12 + x/18 = 1


\begin{gathered} \Rightarrow(x)/(12)+(x)/(18)=1 \\ \\ \Rightarrow(5x)/(36)=1 \\ \\ \Rightarrow x=(36)/(5)\text{ hours} \end{gathered}

Therefore, it will take 36/5 hours to wire the house together.

User Matt Mizumi
by
7.8k points

No related questions found

Welcome to QAmmunity.org, where you can ask questions and receive answers from other members of our community.