P can finish a work in 18 days. Q can finish the same work in 15 days. Q worked for 10 days and left the job. how many days does P alone need to finish the remaining work?
A.
2
B.
4
C.
6
D.
8
Answer: Option C
Explanation:
Work done by P in 1 day = 1/18 Work done by Q in 1 day = 1/15 Work done by Q in 10 days = 10/15 = 2/3 Remaining work = 1 – 2/3 = 1/3 Number of days in which P can finish the remaining work = (1/3) / (1/18) = 6
P can lay railway track between two stations in 16 days. Q can do the same job in 12 days. With the help of R, they completes the job in 4 days. How much days does it take for R alone to complete the work?
A.
9(3/5) days
B.
9(1/5) days
C.
9(2/5) days
D.
10 days
Answer: Option A
Explanation:
Amount of work P can do in 1 day = 1/16 Amount of work Q can do in 1 day = 1/12 Amount of work P, Q and R can together do in 1 day = 1/4 Amount of work R can do in 1 day = 1/4 – (1/16 + 1/12) = 3/16 – 1/12 = 5/48 => Hence R can do the job on 48/5 days = 9 (3/5) days
wo pipes X and Y fill a tank in 15 hrs. and 20 hrs. respectively, while a third pipe ‘Z’ can empty the full tank in 25 hrs. All the three pipes are opened in the beginning. After 10 hrs. Z is closed. In how much time, will the tank be full ?
