Answer:
The actual width of the hair is 20 / 150 = 0.13 mm
Step-by-step explanation:
Scaling
Objects can be represented in a reduced or augmented size by using scaling which is basically multiplying or dividing by a constant factor. We use scaling in several applications of real-life.
The human hair is magnified 150 times by a micro-phtograph. This is the scale factor.
The hair can be seen 2 cm wide in the photograph.
Converting to millimeters, 2 cm = 2*10 = 20 millimeters.
The actual width of the hair is 20 / 150 = 0.13 mm