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V) A train travels a distance of 480 km at a uniform speed. If the speed had been8 km/h less, then it would have taken 3 hours more to cover the same distance. Weneed to find the speed of the train by quadratic equation |
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Answer» ANSWER Let the speed of the train be x km/hr. Then Time taken to TRAVEL a distance of 480km= x 480
hr Time taken by the train to travel a distance of 480km with the speed (x−8)km/hr= x−8 480
hr It is given that if the speed had been 8km/hr LESS, then the train WOULD have taken 3 hours more to cover the same distance ∴ x−8 480
= x 480
+3 ⇒ x−8 480
− x 480
=3⇒ x(x−8) 480(x−x+8)
=3⇒ x(x−8) 480×8
=3 ⇒3x(x−8)=480×8⇒x(x−8)=160×8⇒x 2 −8x−1280=0 This is the required quadratic EQUATION |
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