# Question: A college professor can see objects clearly only if they

A college professor can see objects clearly only if they are between 70 and 500 cm from her eyes. Her optometrist prescribes bifocals (Fig. 25.23) that enable her to see distant objects through the top half of the lenses and read students’ papers at a distance of 25 cm through the lower half. What are the respective powers of the top and bottom lenses?

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