$\"\"$

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A runner ran $\"\"$ in $\"\"$ and then $\"\"$ in $\"\"$ .

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Find Speed $\"\"$ .

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Speed formula : $\"\"$ .

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A runner ran $\"\"$ in $\"\"$ .

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$\"\"$ (Substitute $\"\"$ and $\"\"$ )

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$\"\"$ (Simplify)

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$\"\"$ .

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A runner ran $\"\"$ in $\"\"$ .

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$\"\"$ (Substitute $\"\"$ and $\"\"$ )

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$\"\"$ (Simplify)

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$\"\"$ .

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$\"\"$

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Find the average speed.

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$\"\"$ (Formula for average speed)

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$\"\"$ (Substitute $\"\"$ and $\"\"$ )

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$\"\"$ (Simplify)

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$\"\"$ .

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Therefore, the avarage speed of the runner is $\"\"$ .

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$\"\"$

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The avarage speed of the runner is $\"\"$ .