# Reach Full Speed!

Algebra Level 4

Carlos ran a race at a competition. The course was measured at $${1000\text{ m}}$$ correct to two significant figures and his time was given as $${156\text{ s}}$$ correct to the nearest second. If the difference between his maximum and minimum possible average speed can be expressed as $$\frac{a}{b}\text{ m/s}$$, where $$a$$ and $$b$$ are positive integers, find $$a+b$$.

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