A can do a piece of work in 6 days. B can do it in 5 days. With the assistance of C they completed the work in 2 days. Find in how many days can C alone do it? Choose the correct choice from the following answers.
A) 8.7 days B) 2.0 days C) 6.6 days D) 7.5 days E) 4.4 days
C = 1/2 - 1/6 - 1/5 =2/15   =&gt; 7.5 days   Answer: 7.5 days
<result>D</result>
A can do a piece of work in 6 days. B can do it in 5 days. With the assistance of C they completed the work in 2 days. Find in how many days can C alone do it?