Question

Please solve this quickly....

Answer 1

take the speed of passenger train be x
so speed of express train is x + 14 kmph.
show that 1.68/x - 1.68/x+14 =1 .u will get the answer. Alright

Answer 2

distance = 1.68 km
let avg. speed of passenger train=x
therefore avg. speed of Express train =x+14

let time taken by passenger train = y
therefore time taken by Express train=y-1

now , s×t=d
case 1.(Express train )= (x+14)(y-1)=1.68
xy - x + 14y -14=1.68
xy - x + 14y= 15.68
case 2.(passenger train)=xy=1.68


substracting 2 from 1 =
xy - x +14y -xy = 15.68-1.68
14y - x= 14

from 2. x=1.68/y
using this we get
14y- 1.68/y=14
(14y^2-1.68)/y=14
14y^2-1.68=14y
14y^2-14y-1.68=0

solve for this & u will get ur answer
& put that value in x to get x & y
& finally put the value to get both train's speed.