Question 105914
{{{speed=distance/time}}}
{{{distance=speed*time}}}
{{{time=distance/speed}}}


Let x= speed of the slower train
____x+40=speed of the faster.


It took the same time for the faster one to reach 70 km and the slower one to attain 60km.

time for the slower={{{60/x}}}

time for the faster={{{70/(x+40)}}}


{{{60/x=70/(x+40)}}}

By cross multiplication,

{{{60(x+40)=70x}}}
{{{60x+2400=70x}}}
{{{70x=60x+2400}}}
{{{70x-60x=60x-60x+2400}}}
{{{10x=2400}}}
{{{x=240}}}
{{{x+40=240}}}


Therefore, their soeeds are 200 and 240 km/hr!


Power up,
HyperBrain!