A Train Overtakes Two Persons Who Are Walking In The Same Direction I

1.	A Train Overtakes Two Persons Who Are Walking In The Same Direction In Which The Train Is Going, At The Rate Of 2 Kmph And 4 Kmph And Passes Them Completely In 19 And 20 Seconds Respectively. The Length Of The Train Is:
Answer» Convert the persons Speed in m/sec 2 kmph = (2 x 5/18) m/sec = 5/9 m/sec. 4 kmph = (4 x 5/18 m/sec = 10/9 m/sec. Let the length of the train be x meters and its speed by y m/sec. Relative speed in respect to both PERSON (y - 5/9) and (y - 10/9) FORMULA Used: Time = Distance / speed so x / (y - 5/9) = 19 ---- (1) and x / (y - 10/9) = 20 ---- (2) 9x = 19 (9y - 5) ----- (1) 9x = 20 (9y - 10) ------(2) find the value of x and y 19 (9y - 5) = 20(9y - 10) 171 y - 95 = 180 y -200 => 9y = 105 => y = 105/9 = 35/3 Now find the value fo x by above any equations 9x = 171 35/3 - 95 = 57 35 - 95 9x = 1900 => x = 211.1 meter Convert the persons Speed in m/sec 2 kmph = (2 x 5/18) m/sec = 5/9 m/sec. 4 kmph = (4 x 5/18 m/sec = 10/9 m/sec. Let the length of the train be x meters and its speed by y m/sec. Relative speed in respect to both person (y - 5/9) and (y - 10/9) Formula Used: Time = Distance / speed so x / (y - 5/9) = 19 ---- (1) and x / (y - 10/9) = 20 ---- (2) 9x = 19 (9y - 5) ----- (1) 9x = 20 (9y - 10) ------(2) find the value of x and y 19 (9y - 5) = 20(9y - 10) 171 y - 95 = 180 y -200 => 9y = 105 => y = 105/9 = 35/3 Now find the value fo x by above any equations 9x = 171 35/3 - 95 = 57 35 - 95 9x = 1900 => x = 211.1 meter

A Train Overtakes Two Persons Who Are Walking In The Same Direction In Which The Train Is Going, At The Rate Of 2 Kmph And 4 Kmph And Passes Them Completely In 19 And 20 Seconds Respectively. The Length Of The Train Is:

Answer»

Convert the persons Speed in m/sec

2 kmph = (2 x 5/18) m/sec = 5/9 m/sec.

4 kmph = (4 x 5/18 m/sec = 10/9 m/sec.

Let the length of the train be x meters and its speed by y m/sec.

Relative speed in respect to both PERSON (y - 5/9) and (y - 10/9)

FORMULA Used: Time = Distance / speed

so x / (y - 5/9) = 19 ---- (1)

and x / (y - 10/9) = 20 ---- (2)

9x = 19 (9y - 5) ----- (1)

9x = 20 (9y - 10) ------(2)

find the value of x and y

19 (9y - 5) = 20(9y - 10)

171 y - 95 = 180 y -200 => 9y = 105 => y = 105/9 = 35/3

Now find the value fo x by above any equations

9x = 171 *35/3 - 95 = 57 *35 - 95

9x = 1900 => x = 211.1 meter