Question 1119129
<br>
Let x be the speed of the train in km/hr.<br>
Then the distances traveled in equal amounts of time tell us the speed of the plane is (9/2)x.<br>
And the statement of the problem tells us the speed of the plane is 5x-20.<br>
We have two expressions for the speed of the plane; they must be equal.  So<br>
{{{(9/2)x = 5x-20}}}
{{{(-1/2)x = -20}}}
{{{x = 40}}}<br>
The speed of the train is 40km/hr; the speed of the plane is (9/2)*40 = 180km/hr.