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Since it is a converging lens f = +18 cm (real-is-positive and virtual-is-negative rule)
The object is real therefore u = +12 cm, substituting in the lens formula, then 1 / f = 1 / u + 1 / v or 1 / v = 1 / f – 1 / u = 1 / 18 – 1 / 12 = - 1 / 36
Hence v = - 36 then the image is virtual, erect and same size as the object.
Mutiso answered the question on October 15, 2018 at 17:55
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