If A, B and C together can finish a piece of work in 4 days. A alone in 12 days and B in 18 days, then C alone can do it in?	Choose the correct choice from the following answers
A) 1	B) 7	C) 8	D) 9	E) 6
C = 1/4 - 1/12 – 1/18 = 1/9 =&gt; 9 days'   Answer: 9
<result>D</result>
If A, B and C together can finish a piece of work in 4 days. A alone in 12 days and B in 18 days, then C alone can do it in?