A microscope magnifies 400x. A cell appears to be 8 mm wide. What is its actual width in micrometers? (1 mm = 1000 μm)
Answer
20 μm
How to solve it
1
Apparent width: 8 mm
2
Magnification: 400x
3
Actual: 8 ÷ 400 = 0.02 mm = 20 μm
Hints
Divide apparent size by magnification
Convert mm to micrometers