A and B can do a piece of work in 12 days. With the help of C they finish the work in 3 days. C alone can do that piece of work in? Choose the correct option:
A) 40 days  B) 2 days  C) 4 days  D) 8 days  E) 40 days
4 days   30 days   4 days = 1/3 – 1/12 = 1/4 =&gt; 4 days
<result>C</result>
A and B can do a piece of work in 12 days. With the help of C they finish the work in 3 days. C alone can do that piece of work in?