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A train covered a certain distance at a uniform speed. If the train would have been 6km/h faster, it would have taken 4 hours less than the scheduled time. And, if the train were slower by 6km/h, it would have taken 6 hours more than the scheduled time. Find the length of the journey. anwserb fast |
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Answer» Answer: Let x km/hr be the speed of train Let y be the time taken by the train Distance = speed x time = x y To form the first equation let us consider the given information from the question that is If the train had been 6 km/hr faster,it would have taken 4 hours less than the SCHEDULED time. it clearly says that speed is increased by 6 and time is reduced by 4 So , (x + 6) (y - 4) = x y x y - 4 x + 6 y - 24 = x y x y - x y - 4 x + 6 y = 24 - 4 x + 6 y = 24 divided by (-2) => 2 x - 3 y = -12 ----- (1) To form the second equation let us consider the given information from the question that is If the train were slower by 6km/hr, then it would have taken 6 hours more than the scheduled time. it clearly says that speed is reduced by 6 and time is increased by 6 So , (x - 6) (y + 6) = x y x y + 6 x - 6 y - 36 = x y x y - x y + 6 x - 6 y = 36 6 x - 6 y = 36 divided by (6) => x - y = 6 ----- (2) 2 x - 3 y = -12 (2) x 2 => 2 x - 2 y = 12 (-) (+) (-) --------------- - y = -24 y = 24 Now we have to apply the value of y in the first equation to get value of x Substitute y = 24 in the first equation we get 2 x - 3 (24) = -12 2 x - 72 = -12 2 x = -12 + 72 2 x = 60 x = 60/2 x = 30 Speed of the train = 30 km/hr Time taken by the train = 24 hours Distance covered by the train = x y = 30 x 24 = 720 km Verification: 2 x – 3 y = -12 2(30) - 3(24) = -12 60 - 72 = -12 -12 = -12 Step-by-step explanation: Mark as brainlist |
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