Question 1199913
<pre>
TRAIN     SPEEDS       TIME              DISTANCE

A         r+35         270/(r+35)          270

B          r           200/r               200
</pre>

{{{270/(r+35)=200/r}}}

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{{{270r=200(r+35)}}}

{{{27r=20(r+35)}}}

{{{27r=20r+700}}}

{{{7r=700}}}

{{{r=100}}}

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