1.  A, B and C can complete a piece of work in 24, 6 and 12 days respectively. Working together, they will complete the same work in:
A. 1/24 day
B. 7/24 day
C. 33/7 days
D. 4 days

Answer: Option C

Explanation:

Formula: If A can do a piece of work in n days,

then A's 1 day's work = 1 .
n

(A + B + C)'s 1 day's work = 1 + 1 + 1 = 7 .
24 6 12 24

Formula: If A's 1 day's work = 1 ,
n

then A can finish the work in n days.

So, all the three together will complete the job in:

24 days = 3 3 days.
7 7