Question

1) 24, 32 2) 32, 24 +0, JL A train travels some distance at a constant speed. If the speed of the train would have increased by 15km/hr then it would have required 2 hours less. But if the speed of the train would have decreased by 5km then to cover the same distance it would have required 1 hour more. Find the distance covered by the train. 1) 120 km 2) 240 km 3) 360 km 4) 400 km​

Answer 1

Answer:

$Let x km/hr be the constant speed of the train,</p><p></p><p>Then Time taken to cover 300km=x300hrs</p><p></p><p>Time taken to cover 300km when the speed is increased by 5km/hr=x+5300hours</p><p></p><p></p><p>It is given that the time to cover 300km is reduced by 2 hours</p><p></p><p></p><p>∴x300−x+5300=2</p><p></p><p></p><p>⇒x(x+5)300(x+5)−300x=2⇒2x2+10x=1500</p><p></p><p></p><p>⇒x2+5x−750=0⇒x2+30x−25x−750=0</p><p></p><p></p><p>⇒(x+30)(x−25)=0⇒x=25orx=−30</p><p></p><p></p><p>But x cannot be negative. Therefore x=25</p><p></p><p></p><p>Hence, the original speed of the train is 25km/hr</p><p></p><p></p><p>$