Question

the speed of a train is increased by 5 kilometre per hour it takes 2 hours less in travelling a distance of 300 km find the origional speed of train​

Answer 1

Let the usual speed of the train be =x km\hr

Total distance=300km

∴ Time taken= x300 hrs. ............(1)

New speed of the train=(x+5)km\hr

Time taken= (x+5)300 hrs. ............(2)

According to given condition,

x/300 − x+5/ (300) =2 from (1) and (2)

⇒ 300x+1500−300x /x(x+5) =2

⇒1500=2x² +10x

⇒2x²+10x−1500=0

⇒x² +5x−750=0

⇒(x+30)(x−25)=0

⇒x+30=0 or x−25=0

now comparison

x=−30(rejected) because speed can't be negative ∴x=25

∴ usual speed of the train=25km\hr.

hope this will help u