Question Detail
A can do a job in 16 days, B can do same job in 12 days. With the help of C they did the job in 4 days. C alone can do the same job in how many days ?
- \begin{aligned} 6\frac{1}{2}days \end{aligned}
- \begin{aligned} 7\frac{1}{2}days \end{aligned}
- \begin{aligned} 8\frac{3}{5}days \end{aligned}
- \begin{aligned} 9\frac{3}{5}days \end{aligned}
Answer: Option D
Explanation:
In this question we having, A's work, B's work and A+B+C work. We need to calculate C's work.
We can do it by,
(A+B+C)'s work - (A's work + B's work).
Let's solve it now:
C's 1 day work =
\begin{aligned}
\frac{1}{4}- \left(\frac{1}{16} +\frac{1}{12} \right) \\
=\left(\frac{1}{4} - \frac{7}{48} \right) \\
= \frac{5}{48}
\end{aligned}
So C can alone finish the job in 48/5 days,
Which is =
\begin{aligned} 9\frac{3}{5}days \end{aligned}