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Quantity I: The speed of the stream is 3 km/hr. A boat goes 30 km oupstream and comes back again to the starting point in 175 min. Then sped of the boat in still water ( in km/hr): Quantity II: A man in a car travels a certain distance in 20 min. He observes that he corossed 8 bus stops. If distance between two bus stops are 1000m, then the speed at which the car is travelling (in km/hr)A. Quantity - I `gt` Quantity -IisB. Quantity `-I lt` Quantituy - IIC. Quantity `-Ige` Quantity - IID. Quantity `- I =` Quantity - II |
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Answer» Explanation : Quantity - I Let speed of the Boat = x Speed of the stream = 3 km/hr `(30)/(x-3)+(30)/(x+3)=175/60` `(62x)/(x^(2)-9)=35/12` `7x^(2)-144x-63=0` `7x^(2)-147x+3x-63=0` `thereforex=21` Quantity - II Bus stops = 8 Distance between bus stops = 1 km Total distance `=1xx7=7` km Let speed of car = x Time = 20 min `(7)/(20)xx(60)/(1)=21` km Hence, Quantity - II = Quantity - I |
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