A can do a work in 15 days and B in 20 days. If they work on it together for 4 days, then the fraction of the work that is left is :
A's 1 day's work = 1/15
B's 1 day's work = 1/20
(A + B)'s 1 day's work = ( (1/15) + (1/20) ) = 7/60
(A + B)'s 4 day's work = ( (7/60) x 4 ) = 7/15
Therefore, Remaining work = ( 1 - (7/15) ) = 8/15
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. 9 (1/5) days
B. 9 (2/5) days
C. 9 (3/5) days
9 (3/5) days
(A + B + C)'s 1 day's work = 1/4
A's 1 day's work = 1/16
B's 1 day's work = 1/12
=> C's 1 day's work = 1/4 - ( (1/16) + (1/12) ) = 5/48
So, C alone can do the work in 48/5 = 9 (3/5) days
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) x 2 = 1/10
(A + B + C)'s 1 day's work = (1/20) + (1/30) + (1/60) = 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
A is thrice as good as workman as B and therefore is able to finish a job in 60 days less than B. Working together, they can do it in:
A. 20 days
B. 22 (1/2) days
C. 25 days
D. 25 (1/2) days
22 (1/2) days
Ratio of times taken by A and B = 1 : 3
The time difference is (3 - 1) 2 days while B take 3 days and A takes 1 day.
If difference of time is 2 days, B takes 3 days.
If difference of time is 60 days, B takes (3/2) x 60 = 90 days
So, A takes 30 days to do the work.
A's 1 day's work = 1/30
B's 1 day's work = 1/90
(A + B)'s 1 day's work = (1/30) + (1/90) = 4/90 = 2/45
=> A and B together can do the work in 45/2 = 22 (1/2) days
A alone can do a piece of work in 6 days and B alone in 8 days. A and B undertook to do it for Rs. 3200. With the help of C, they completed the work in 3 days. How much is to be paid to C?
A. Rs. 375
B. Rs. 400
C. Rs. 600
D. Rs. 800
C's 1 day's work = (1/3) - ( (1/6) + (1/8) ) = 1/24
A's wages : B's wages : C's wages = 1/6 : 1/8 : 1/24 = 4 : 3: 1
=> C's share for 3 days = Rs. ( 3 x (1/24) x 3200 ) = Rs. 400
A man can do a job in 15 days. His father takes 20 days and his son finishes it in 25 days. How long will they take to complete the job if they all work together?
A. Less than 6 days
B. Exactly 6 days
C. Approximately 6.4 days
D. More than 10 days
Approximately 6.4 days
1 day's work of the three persons = (1/15+1/20+1/25)
So, all the three together will complete the work in = 300/47
= 6.4 days.
16 men can complete a work in 35 days. In many days can 28 men complete the same piece of work?
A. 18 days
B. 20 days
C. 22 days
D. 16 days
E. None of these
24 men working 8 hours a day can finish a work in 10 days. Worked at the rate of 10 hours a day, the number of men required to finish the same work in 6 days is :
E. None of these
The average monthly income of A and B is Rs. 5050. The average monthly income of B and C is Rs. 6250 and the average monthly income of A and C is Rs. 5200. What is the monthly income of A?
If 80 lamps can be lighted, 5 hours per day for 10 days for Rs. 21,25, then the number of lamps, which can be lighted 4 hours daily for 30 days, for Rs. 76.50, is:
A person works on a project and completes 5/8 of the job in 10 days. At this rate, how many more days will he it take to finish the job?
10 men, working 6 hours a day can complete a work in 18 days. How many hours a day must 15 men work to complete the same work in 12 days?
x men working x hours per day can do x units of a work in x days. How much work can be completed by y men working y hours per day in y days?
A. x2/y2 units
B. y3/x2 units
C. x3/y2 units
D. y2/x2 units
If 18 binders bind 900 books in 10 days, how many binders will be required to bind 660 books in 12 days?
A tank is filled in 5 hours by theree pipes A, B and C. The pipe C is twice as fast as B and B is twice as fast as A. How much time will pipe A alone take to fill the tank ?
A. 35 hours
B. 25 hours
C. 20 hours
D. Cannot determined
E. None of these
A can lay railway track between two given stations in 16 days and B can do the same job in 12 days. With the help of C, they did the job in 4 days only. Then, C alone can do the job in:
D. 10 days
A and B can do a piece of work in 72 days; B and C can do it in 120 days; A and C can do it 90 days. In what time can A alone do it?
A. 80 days
B. 100 days
C. 120 days
D. 150 days
12 years ago the ratio between the ages of A and B was 3 : 4 respectively. The present age of A is 3 3/4 times of C's present age. If C's present age is 10 Years, then what is B's present age? (in years)
Pipes A and B fill a tank in 5 and 6 hours respectively. Pipe C can empty it in 12 hours. If all the three pipes are opened together, then the tank will be filled in
A. 1 13/17 hours
B. 2 8/11 hours
C. 3 9/17 hours
D. 4 1/2 hours
3 9/17 hours
A pump can fill a tank with water in 2 hours. Because of a leak, it tookhours to fill the tank. The leak can drain all the water of the tank in:
B. 7 hrs
C. 8 hrs
D. 14 hrs
A and B can complete a work in 15 days and 10 days respectively. They started doing the work together but after 2 days B had to leave and A alone completed the remaining work. The whole work was completed in:
A. 8 days
B. 10 days
C. 12 days
D. 15 days
Two pipes A and B can fill a tank in 12 minutes and 15 minutes respectively. If both the taps are opened simultaneously, and the tap A is closed after 3 minutes, then how much more time will it take to fill the tank by tap B?
A. 7 min 15 sec
B. 7 min 45 sec
C. 8 min 5 sec
D. 8 min 15 sec
8 min 15 sec
A tank is fitted with 8 pipes, some of them that fill the tank and others that are waste pipe meant to empty the tank. Each of the pipes that fill the tank can fill it in 8 hours, while each of those that empty the tank can empty it in 6 hours. If all the pipes are kept open when the tank is full, it will take exactly 6 hours for the tank to empty. How many of these are fill pipes?
In a camp, 95 men had provisions for 200 days. After 5 days, 30 men left the camp. For how many days will the remaining food last now?
D. None of these
Two pipes A and B can fill a tank in 20 and 30 minutes respectively. If both the pipes are used together, then how long will it take to fill the tank?
A. 12 min
B. 15 min
C. 25 min
D. 50 min
If 8 men can reap 80 hectares 24 days, then how many hectares can 36 men reap in 30 days?
7 person can do a piece of work in 21 days. How many persons are required to do a piece of work in 3 days?
A, B and C start at the same time in the same direction to run around a circular stadium. A completes a round in 252 seconds, B in 308 seconds and C in 198 seconds, all starting at the same point. After what time will they meet again at the starting point?
A. 26 minutes 18 seconds
B. 42 minutes 36 seconds
C. 42 minutes
D. 46 minutes 12 seconds
46 minutes 12 seconds
A and B working together can finish a job in T days. If A works alone and completes the job, he will take T+5 days. If B works alone and completes the same job, he will take T+45 days. What is T?
A. 25 Days
B. 60 Days
C. 15 Days
D. None of these
Two pipes A and B can fill a cistern in 12 minutes and 16 minutes respectively. If both the pipes are opened together, then after how much time B should be closed so that the tank is full in 9 minutes?
A. 3 min and 30 sec
B. 4 min and 30 sec
C. 4 min
D. 4 min 77 sec