by abdulsaboor » Thu Oct 11, 2012 9:37 am
2.
A can lay railway track between two given stations in 16 days and B can do the same job in 12 days. With help of C, they did the job in 4 days only. Then, C alone can do the job in:
A.
46/5 days
B.
47/5 days
C.
48/5 days
D. 10
3.
A, B and C can do a piece of work in 20, 30 and 60 days respectively. In how many days can A do the work if he is assisted by B and C on every third day?
A. 12 days
B. 15 days
C. 16 days
D. 18 days
A's 2 day's work =[1/20]*2=1/10
(A + B + C)'s 1 day's work =1/20 + 1/30 +1/60 =6/60=1/10
Work done in 3 days =1/10 +1/10=1/5
Now, 1/5 work is done in 3 days.
Whole work will be done in (3 x 5) = 15 days.