# By how many meters can A beat C in the race

A beats B by 200 m in arace of 800 m.B beats C by 100 m in a 1000 m race. 1)Approximately by how many meters can A beat C in a race of 560m? 2)Approximately by how many meters can A beat C in a race of 500 m?

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This is the tenth homework question you ask in the last few days without showing the least work or thought of your own. I'm starting to get really tired of this. Moreover, I told you already that the number-theory tag is definitely not appropriate for this kind of questions. Please read this page attentively. –  t.b. Apr 26 '11 at 15:41

Hint: If the speeds of $A$, $B$ and $C$ are $a$, $b$ and $c$ metres per second respectively, then what is the relationship between $a$ and $b$, and between $b$ and $c$, and so between $a$ and $c$? Then use this to answer your questions.
For example, $A$ runs $800$ metres in the same time it takes $B$ to run $800-200=600$ metres so $\frac{a}{b}=\frac{800}{600}$.