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. In how many hours B can complete the work ?  Choose one:
A) 10 hours
B) 12 hours
C) 16 hours
D) 18 hours
E) 20 hours
Explanation:   Work done by A in 1 hour = 1/4   Work done by 12 hours and C in 1 hour = 1/3   Work done by A and C in 1 hour = 1/2   Work done by A,12 hours and C in 1 hour = (1/4)+(1/3) = 7/12   Work done by 12 hours in 1 hour = (7/12)–(1/2) = 1/12   =&gt; 12 hours alone can complete the work in 12 hour   Option 12 hours
<result>B</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. In how many hours B can complete the work ?