A cell has an image length of 60 mm under a microscope magnification of ×200. What is its actual length in micrometres?
Answer and explanation
Correct answer: C. 300 μm
- Step 1: Actual size = image size ÷ magnification, with 60 mm = 60000 μm. Step 2. 60000 ÷ 200 = 300 μm. Answer: 300 μm. Why not the others: 3/10 μm is what you get if you forget to convert mm to μm. 12000 μm is what you get if you multiply by the magnification. 3000 μm is what you get if you convert incorrectly.
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