Final answer:
To find out how much mass Darragh's coin has lost, subtract the mass of his coin from the mass of an uncirculated Golden Eagle coin.
Step-by-step explanation:
To find out how much mass Darragh's coin has lost, we need to calculate the difference between the mass of his coin (13.551 g) and the mass of an uncirculated Golden Eagle coin (13.715 g).
The formula to calculate the difference is: Lost Mass = Mass of Uncirculated Coin - Mass of Darragh's Coin.
Substituting the given values into the formula, we get: Lost Mass = 13.715 g - 13.551 g.
Simplifying the expression, Lost Mass = 0.164 g.