A and B can do a piece of work in 11 days. With the help of C they finish the work in 5 days. C alone can do that piece of work in?  Answers.
A) 15.5 days B) 19.5 days C) 17.5 days D) 9.2 days E) 18.5 days
C = 1/5 – 1/11 = 6/55 =&gt; 9.2 days   ANSWER:9.2 days
<result>D</result>
A and B can do a piece of work in 11 days. With the help of C they finish the work in 5 days. C alone can do that piece of work in?