Question

Ans.: iv)If first train takes 3 hrs to cover the distance, then find the speed of second train a) 80 km/hr b) 100 km/hr c) 50 km/hr d) 30 km/hr if. speed of first train is x/300hr and speed of 2nd train is 300/x-150hr​

Answer 1

Answer​

x(x+5)

300x+1500−300x

​

=2

⇒1500=2x  

2

+10x

⇒2x  

2

+10x−1500=0

⇒x  

2

+5x−750=0

⇒(x+30)(x−25)=0

⇒x+30=0 or x−25=0

x=−30(rejected) ∴x=25

∴ usual speed of the train=25km\hr.