Question

An experienced carpenter can frame a house twice as fast as an apprentice. Working together, it takes the carpenters 2 days. How long would it take the apprentice working alone?

Answer 1

Answer:

6 days

Step-by-step explanation:

Let the time taken by Carpenter working alone = $C$ days

Then time taken by apprentice alone = Twice as that of taken by Carpenter = 2$C$ days

Time taken working together = 2 days

Work done in one day working together = $\frac{1}{2}$

Work done in one day by Carpenter working alone = $\frac{1}{C}$

Work done in one day by apprentice working alone = $\frac{1}{2C}$

Work done in one day by Carpenter working alone + Work done in one day by Carpenter working alone =  $\frac{1}{C}$+$\frac{1}{2C}$ = Work done in one day working together = $\frac{1}{2}$

$\dfrac{1}{C}+\dfrac{1}{2C}=\dfrac{1}{2}\\\Rightarrow \dfrac{2+1}{2C}=\dfrac{1}{2}\\\Rightarrow C = 3\ days$

Time taken by Carpenter alone to complete the work = 3 days

Time taken by Apprentice alone to complete the work = 3 $\times$ 2= 6 days