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Auki't travelt eom to hone partotk Ttrain anel partly by Car Hees g hr.train and the rest by Luruttandao nu'aLona er he Karel 2ootra in |
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Answer» Case 1:--------------- Total distance = 600kmDistance covered by train: 120kmTime taken by train: (120)/x km/h [Let 'x' be the speed of the train]Distance covered by car: (600-120) = 480kmTime taken by car: (480)/y km/h [Let 'y' be the speed of the car] Total time taken: (120)/x + (480)/y = 8 or (10)/x + (40)/y = 2/3 or (30)/x + (120)/y= 2 ...... (1) Case II:--------------Total distance covered by train: 200 kmTotal time taken by train: (200)/x km/hTotal distance covered by car: (600-200) = 400 kmTotal time taken by car: (400)/y km/h Total time taken: 8(20/60) = (25)/3(200)/x + (400)/y = (25)/3or (600)x + (1200)/y = 25 ..... (2) Let 1/x be u and 1/y be v .... (3)Equations are then:600u + 1200v = 2530u + 120v = 2Multiplying equation (1) by 20 and subtracting the equations we get:1200v = 15 ; v = (15)/(1200)Since, 1/y = vy = (1200)/3 = 80y = 80 km/h So, the speed of the car is 80 km/h.Hence the speed of the train,Multiplying equation (1) by 10 and subtracting equations we get:300u = 5u = 5/(300)Since, 1/x = u x = (300)/5 ; x = 60 km/hr |
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