A takes twice as much time as B & C takes thrice as much time as B to finish a piece of work. Working together they can finish the work in 18 days. The no. of days need for B to do the work alone is?
Choose the correct choice from the following options:
A) 30 days	B) 31 days	C) 33 days	D) 41 days	E) 52 days

Rationale: let a takes x days to complete the work , then b takes x / 2 days and c takes 3 x / 2 days to complete the work . a , b and c together complete the work in 18 days in 1 day , all they together can do = > 1 / x + 2 / x + 2 / 3 x = 1 / 18 3 + 6 + 2 / 3 x = 1 / 18 3 x 23 x 2 = 18 x = 66 days the number of days b alone takes to finish the work = x / 2 = 33 days c
Answer: C