1.  A takes twice as much time as B or thrice as much time as C to finish a piece of work. Working together, they can finish the work in 2 days. B can do the work alone in:
A. 4 days
B. 6 days
C. 8 days
D. 12 days

Answer: Option B

Explanation:

Suppose A, B and C take :

x, x and x days respectively to finish the work.
2 3

Then, 1 + 2 + 3 = 1
x x x 2

6 = 1
x 2

x = 12.

So, B takes (12/2) = 6 days to finish the work.