Question

A can do a piece of work in $8$ days and B can do it in $4$ days . Both of them working together will finish it in?

• A. $12$ days
• B. $4$ days
• C. $2$ days
• D. $2\frac{2}{3}$ days

Answer 1

Answer: (D)

$2\frac{2}{3}$ days

Given that $A,B$ does the work in $8$,$4$ days; if total work be $x;$

$\Rightarrow$work done in $1$ day by $A$, $B$ is $\frac{x}{8},\frac{x}{4}$.

$\Rightarrow$if they both work for one day then work done will be

$\Rightarrow$$\frac{x}{8}+\frac{x}{4}=\frac{3x}{8}$.

$\Rightarrow$Then total work done $x$ will take $\frac{8}{3}=2\frac{2}{3}$ days .... (using proportions.)