A & B can separately do a piece of work in 20 & 15 days. They worked together for 6 days, after which B was replaced by C. The work was finished in next 5 days. The no.of days in which C alone could do the work is
Choose the correct choice from the following.
A) 10 days  B) 20 days  C) 30 days  D) 40 days  E) 50 days
B worked for 6 days =&gt; In 6 days B completed = 6 x 1 15   = 2 5   th work   A worked for first 6 days and later 4 days =&gt; In 10 days A completed = 10 x 1 20   = 1 2   of the work   Total work done by A and B = 2 5   + 1 2   = 4+5 10   = 9 10   Balance work = 1- 9 10   = 1 10   th of total work   Balance work was completed by C in 5 days   C can do 1/10 of the work in 5 days. Therefore C alone can do the work in 50 days.   50 days
<result>E</result>
A & B can separately do a piece of work in 20 & 15 days. They worked together for 6 days, after which B was replaced by C. The work was finished in next 5 days. The no.of days in which C alone could do the work is