Question 124082
Distance = speed x time.

Let T be the time for the express train.  Then the time for the first train is T+2.

The distance covered by the first train is therefore {{{75*(T+2)}}}

The distance covered by the express train is {{{125*T}}}

Equating the distances:

{{{75*(T+2)=125*T}}}

{{{75*T+150=125*T}}}

Subtracting 75*T from both sides:

{{{150=50*T}}}

{{{3=T}}}

Substitute this value for T into the distance formula for the express train:

{{{D=125*T}}}  {{{D=125*3}}}  {{{D=375}}}

So they will meet 375 km from the train station.  Check by substituting into the equation for the first train.

{{{D=75*(T+2)}}}  {{{375=75*(T+2)}}}  {{{5=T+2}}}  {{{3=T}}}

Solution checks.