- Zarqa on Carlyle’s work On Heroes, Hero Worship and the Heroic in History is a course of ?
- Shokat Hussain Khan on How many districts are in Sindh ?
- Hamad on Who was the Abul Kalam Azad?
- Shokat Hussain Khan on Who was the Abul Kalam Azad?
Two pipes A and B can separately fill a cistern in 60 min and 75 min respectively. There is a third pipe in the bottom of the cistern to empty it. If all the three pipes are simultaneously opened, then the cistern is full in 50 min. In how much time, the third pipe alone can empty the cistern?
Hamad Pipes and Cisterns 28/03/2023
A. 90 min
B. 100 min
C. 110 min
D. 120 min
Work done by the third pipe in 1 min = 1/50 – (1/60 + 1/75) = – 1/100.
[-ve sign means emptying]
The third pipe alone can empty the cistern in 100 min.
- Two pipes A and B can fill a cistern in 20 and 30 minutes respectively, and a third pipe C can empty it in 40 minutes. How long will it take to fill the cistern if all the three are opened at the same time?
- A. 19 1/7 min B. 15 1/7 min C. 17 1/7 min D. 7 1/7 min...
- Two pipes can separately fill a tank in 20 and 30 hours respectively. Both the pipes are opened to fill the tank but when the tank is full, a leak develops in the tank through which one-third of water supplied by both the pipes goes out. What is the total time taken to fill the tank?
- A. 18 hrs B. 16 hrs C. 15 hrs D. 12 hrs...
- Pipe A can fill a tank in 6 hours. Due to a leak at the bottom, it takes 9 hours for the pipe A to fill the tank. In what time can the leak alone empty the full tank?
- A. 16 hours B. 15 hours C. 18 hours D. 17 hours...
- One pipe can fill a tank three times as fast as another pipe. If together the two pipes can fill tank in 36 min, then the slower pipe alone will be able to fill the tank in?
- A. 81 min B. 108 min C. 144 min D. 192 min...
- One top can fill a cistern in 2 hours and another can empty the cistern in 3 hours. How long will they take to fill the cistern if both the taps are opened?
- A. 5 Hours B. 6 Hours C. 7 Hours D. 8 Hours...
Leave a Reply