A train covers a distance of 90 km in 90 minutes. . Find the time taken by the train to cross an electric pole if the length of the train is 300m.
Answers
Answered by
0
Answer:
45km/hr
Step-by-step explanation:
Let original speed =xkm/hr
⇒ Time taken to travel = 90/x hr
⇒ New speed =(x+15)km/hr
⇒ Time taken to travel =
x+15/
90
hr
∴
x/
90
=
x+15/
90
+
2
1
⇒
x
90
−
x+15
90
=
2
1
⇒ 90(
x
1
−
x+15
1
)=
2
1
⇒
x(x+15)
x+15−x
=
180
1
⇒ 15×180=x(x+15)
⇒ 2700=x
2
+15x
⇒ x
2
+15x−2700=0
⇒ x
2
+60x−45x−2700=0
⇒ x(x+60)−45(x+60)=0
⇒ (x+60)(x−45)=0
Speed can not be negative.
∴ The original speed of the train is 45km/hr
MARK ME AS BRAINLEST
Similar questions