Final answer:
A dental cartridge of 3% concentration contains 54 mg of local anesthetic.
Step-by-step explanation:
The amount of local anesthetic in a dental cartridge of 3% concentration can be calculated by multiplying the concentration by the volume of the cartridge. A standard dental cartridge typically contains 1.8 mL of solution. To find the amount of anesthetic, convert the concentration from a percentage to a decimal: 3% = 0.03. Now multiply the concentration by the volume: 0.03 * 1.8 = 0.054 mL or 54 mg.