A and B can do a work in 2 days, B and C in 4 days and C and A in 6 days. In how many days will the work be completed, if all three of them work together?
Choose the correct choice from the following answers:	A) 10 / 12	B) 16 / 28	C) 24 / 11	D) 42 / 16	E) 18 / 12

Rationale: one day work of a and b = 1 / 2 one day work of b and c = 1 / 4 one day work of c and a = 1 / 6 2 ( a + b + c ) = 1 / 2 + 1 / 4 + 1 / 6 . 2 ( a + b + c ) = 11 / 12 ( a + b + c ) = 11 / 24 number of days required = 24 / 11 days . answer : c
Answer: C