Answer: 5,700 mg
Step-by-step explanation: First, put all the measurements at the same unit. I chose g.
25 mg = 0.025g
120 g = 120 g
0.5 kg = 500 g
5,700 mg = 5.7 mg
We can rule out 120 g and 500 g because it would be too heavy for a coin. 0.025 g is too light for a coin. This way, we can choose the 5.7 g
