A can do a piece of work in 4 hours . A and C together can do it in just 2 hours, while B and C together need 3 hours to finish the same work. B alone can complete the work in --- hours.  Choose the correct choice from the following options:
A) 65 B) 85 C) 48 D) 12 E) 25
Explanation :   Work done by A in 1 hour = 1/4   Work done by B and C in 1 hour = 1/3   Work done by A and C in 1 hour = 1/2   Work done by A,B and C in 1 hour = 1/4+1/3 = 7/12   Work done by B in 1 hour = 7/12 – 1/2 = 1/12 =&gt; B alone can complete the work in 12 hours   ANSWER:12
<result>D</result>
A can do a piece of work in 4 hours . A and C together can do it in just 2 hours, while B and C together need 3 hours to finish the same work. B alone can complete the work in --- hours.