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A train travels 360 km at a uniform speed.If the speed had been 5km/h more, it would have taken 1 hour less for the same journey.Find the speed of the train. |
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Answer» Assumption Original speed of train :- = p km/h Also, = 360/p hours So, Time taken to cover 360 km (Combined) :- = 360/p + 5 hr Situation :- ⇒ 360/p - 360/p + 5 = 1 ⇒ 360(p + 5 - p)/p(p + 5) = 1 ⇒ 360(5) = p² + 5p ⇒ 1800 = p² + 5p ⇒ p² + 5p - 1800 = 0 ⇒ p² + 45p - 40p - 1800 = 0 ⇒ (p + 45) (p - 40) = 0 ⇒ p = -45 Also ⇒ p = 40 [As negative value is not APPLICABLE for speed] So, ⇒ p = 40 km/hr. Therefore, Speed of the train = 40 km/h |
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