Answer:
A single penny is 1.52 mm thick.
A stack of 20 pennies would be 30.4 mm thick.
Explanation:
Question #1: Determining the thickness of a single penny:
Since a stack of 12 pennies is 18.24 mm high, we can determine the thickness of one penny by dividing the thickness of the stack by the total number of pennies in the stack:
Thickness of one penny = Thickness of entire stack / Total number of pennies in 12-penny stack
Thickness of one penny = 18.24 / 12
Thickness of one penny = 1.52
Thus, each penny is 1.52 mm thick.
Question #2: Determining the thickness of a 20-penny stack:
Since we now know that each penny is 1.52 mm thick, we can determine the thickness of a 20-penny stack by multiplying 1.52 by 20:
Thickness of 20-penny stack = Thickness of one penny * total number of pennies in 20-penny stack
Thickness of 20-penny stack = 1.52 * 20
Thickness of 20-penny stack = 30.4
Thus, a stack of 20 pennies would be 30.4 mm thick.