Question

A 75 meters long train is running at a certain speed.A man is riding on a bicycle
at 9 Km/ hr in the direction of the train and the train passes him in 7.5 secs.
Find the speed of the train

Answer 1

Answer:

Let the speed of the train be x m/s

Speed of the 1

st

man =6 km/hr = (6×

18

5

) m/s =

3

5

m/s

⇒

(x−5/3)

75

=

2

15

⇒150=15×

3

(3x−5)

=15x−25

⇒15x=175

⇒x=

15

175

=

3

35

m/s

Let the speed of the second man be y m/s.

Then

(

3

35

−y)

75

=

4

27

⇒300=27×(

3

35−3y

)=315−27y

⇒27y=15

⇒y=

27

15

m/s =(

27

15

×

5

18

) km/hr =2 km/hr