Pipe A can fill a tank in X hours. Pipe B can empty it in 15 hours. If both the pipes are opened together, then the tank will be filled in 7 hours and 30 minutes. Find X.
5
Given,
Pipe A can fill a tank in X hours
Pipe B can empty a full tank in 15 hours
If both Pipe A and Pipe B are open, the tank gets filled in 7 hours 30 minutes = (7 + 1/2) = 15/2 hours
Formula:
Total work = Efficiency × Time taken
Calculation:
Total work = 15 units
⇒ Efficiency of B = (-1) unit/hour
Let the efficiency of A be t, then
t – 1 = 2
⇒ t = 2 + 1
⇒ t = 3 units/hour
∴ Pipe A alone can fill the tank = 15/3 = 5 hours
Important Questions from Work Efficiency
A and B together can complete a certain work in 20 days whereas B and C together can complete it in 24 days. If A is twice as good a workman as C, then in what time will B alone do 40% of the same work?
14 men can complete a work in 15 days. If 21 men are employed, then in how many days will they complete the same work?
A can do a certain work in 15 days, while B can do the same work in 21 days. If they work together, then in how many days will the same work be completed?
To do a certain work, A and B work on alternate days with B beginning the work on the first day. A alone can complete the same work in 24 days. If the work gets completed in \(11 \frac{1}{3}\) days, then B alone can complete \(\rm \frac{7}{9}^{th}\) part of the original work in:
Two men and 7 women can complete a work in 28 days whereas 6 men and 16 women can do the same work in 11 days. In how many days can 7 men complete the same work?
