Magnification Formula in Microscopy

Steps:

• Recall the standard magnification formula: M = image size / actual size, or equivalently, image size = M × actual size.
• Identify equations that match this direct proportionality without inversions or unrelated terms.
• Eliminate options with reciprocal relationships (e.g., actual size = image size / M is valid, but mismatches like size / M for image would be incorrect).
• Select the pair aligning with both direct and inverse forms of the formula.

Why A is correct:

• Equations 1 and 3 express the core relationship: M = image / actual and actual = image / M, per the definition of magnification as a ratio.

Why the others are wrong:

• B includes 4, which likely inverts the relationship incorrectly (e.g., M = actual / image).
• C pairs 2, possibly a flawed variant like image = actual / M, violating proportionality.
• D combines two incorrect inversions, ignoring the standard formula.

Not enough information on exact equations 1–4, but based on standard microscopy principles, A fits.

Final answer: A