time and distance short test 6 last question

Let the distance between A and B be d.

Speed of superfast train = 2E and speed of passenger train = E/2

So, d/2E + d/(E/2) = 1 => d = 2E/5

Let the speed of the passenger train in the second case be x
In the second case, d/4E + d/x = 2/3

Substituting for d and solving for x, we get, x = 12E/17

So, ratio of speeds = 12E/17 / 4E = 3 : 17, which is approximately equal to 1 : 6