# Moving Screen & Objects!

A thin biconvex lens of focal length $$f=25 \text{ cm}$$ forms a real image of an object on a screen. The object is separated by $$5\text{ cm}$$ from the lens. The screen is drawn closer to the lens by a distance of $$18 \text{ cm}$$. Through what distance must the object be shifted so that the image is again formed one the screen?

Give your answers in $$\text{ mm}$$.

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