Answer: 2 inches
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Step-by-step explanation:
The area of any given sheet of paper is 8.5*11 = 93.5 square inches.
Divide the volume over this area to get the height of the stack
187/(93.5) = 2
The stack is 2 inches tall.
Extra info: The thickness of each piece of paper is 2/500 = 0.004 of an inch which approximates to about 0.1016 mm.