Let the total number of scholars in the school be x. Number of infants under 7 = (25 x)/100= x/4 ∴ Remaining scholars = x- x/4 = (3 x)/4 ∵ Number of girls above 7 = 4/5 of Number of boys above 7 Now, 120 = 4/5× number of boys above 7 Number of boy above 7 = 150 ∴ 3x/4 = 120 + 150 ⇒ (3 x)/4 = 270 ⟺ x = 360
Pipe T can empty a completely filled tank in 50 hours. Pipe R and T together can fill an empty tank completely in (z+5) hours. The efficiency of pipe R ...
Pipes A and B can fill a tank in 43.2 minutes and 108 minutes, respectively. Pipe C can empty it at 3 litres/minute. When all the three pipes are opened...
Tap A can fill a tank in 20 hours and tap B can emptied it is 25 hours. Tap A starts filling and they opened for 1 hour each alternatively in what time ...
A pump can fill a tank with water in 2 hours. Because of a leak in the tank it was taking 7/3 hours to fill the tank. The leak can drain all the water o...
A tank can be filled by two pipes, A and B, in 15 minutes and 20 minutes, respectively. Both pipes are opened together, but after 5 minutes, pipe A is c...
Pipe Q and Pipe R together can fill a tank in 25 minutes. With Pipe S, all three pipes can fill the tank in 30 minutes. Pipe Q and Pipe T together can f...
Pipe ‘A’ can fill 25% of a tank in 3 hours while pipe ‘B’ takes 30 hours to empty fully filled tank. Pipe ‘A’ is opened alone when the tank ...
Pipes A and B alone can fill a tank in 12 minutes and 18 minutes, respectively, while pipe C alone can empty the full tank in 36 minutes. If all the pip...
Pipe A and B can fill the pool in 36 minutes and 48 minutes, respectively. Pipe C can empty half filled pool in 36 minutes. If all the pipes are opened ...
Pipe ‘A’ and pipe ‘B’, together can fill 20% of a tank in 7 hours while pipe ‘C’ takes 40 hours to empty it. ...
