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Answer» चाल बराबर दूरी / समयमाना चाल x किलोमीटर प्रति घंटा है Let the original speed of the train be x km/h.Time taken to cover a distance of 360 km = 360/x hours. दूरी कवर करने में लगा समयNew speed of the train = (x+5) km/h.Time taken to cover a distance of 360 km at new speed = 360/x+5 hours.Since, the train takes 1 hour less time,∴ 360/x - 360/ x+5 = 1⇒360 (x+5-x)/x(x+5) = 1⇒360 (5) = x² + 5x⇒1800 = x² + 5x⇒x² + 5x - 1800 = 0⇒x² + 45x - 40x - 1800 = 0⇒x (x+45) - 40( x +45) = 0⇒(x+45) (x-40) = 0⇒x = (-45), 40But since speed cannot be in negative.∴ x = 40 km/hr.Hence, the original speed of the train is 40 km/h. |
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