Let A be closed after x minutes. Then, Part filled by (A + B) in x min. + part filled by B in (12 – x) min. = 1 x (1/12 + 1/16 ) + (12 – x ) × 1/16 = 1 ⟹ (7 x)/48 + (12 - x)/16 = 1 ⟹ (7 x)/48 + 3/4 - x/16 = 1 ⟹ (4 x)/48 = 1/4 ∴ x = 3 ∴ Hence, A must be closed after 3 minutes.
Two cars, 'A' and 'B,' are heading towards each other on a straight road. Car 'A' is traveling at a speed of 56 km/h, while Car 'B' is moving at 34 km/h...
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A bus takes 10 seconds to pass a standing man and 28 seconds to pass a traffic light, which is 405 meters long. Determine the time it takes for the bus ...
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It takes 8 hours less to travel from point 'E' to point 'F' at a speed of 60 km/h than it takes to travel the same distance at 24 km/h. If 30% of the di...
A train 200 m long passes a pole in 10 seconds. How long will it take to pass another train 300 m long running in the opposite direction at a speed of 3...
Train P starts from Lucknow to Dehradun at 11:55 am with an average speed of 27.5 m/s. Train Q starts from Dehradunto Lucknowat 1:35 pm with an average ...
A car running with a speed of 52 km/hr takes 4 hours to go from 'A' to 'B'. If on the way back from 'B' to 'A', the car takes 20% less time than it take...
1200 metres long train crosses a man who is moving in the same direction with a certain speed, in 30 seconds. If the same train can cross a tree in 20 s...
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