Question

Two trains of length 150 metre and 180 metre respectively are running in opposite direction on parallel tracks if the speed of 50 km per hour and 50 km per hour respectively in what time will they cross each other

Answer 1

Answer:

let the first train be 'x'km p/h

and the second train be 'y' h

Explanation:

by problem

150/× + 100/y =50

3/× + 2/y = 1______(1)

180/× + 100/y = 50

90/× +50/y = 25_____(2)

put 1/×=a , 1/y= b

3a+2b=1____(3)

90a+50b=25______(4)

solving eq 3 or 4 we get value A &B

eq(3)×90 and eq(4)×3

270a+180b=90

270a+150b=3

_ _ _

___________

0 _ 30b=_87

__________

b=87/30=2.9