Final answer:
The percent decrease in the price of a sandwich from $6 to $4 is approximately 33.33%, calculated using the percent change formula.
Step-by-step explanation:
To calculate the percent decrease in the price of a sandwich we use the formula for percent change, which is (New Value - Original Value) / Original Value × 100%. The original price of the sandwich is $6 and the new price is $4. So the price decrease is $6 - $4 = $2.
Now, we apply the formula for percent change:
(2 / 6) × 100% = (1 / 3) × 100% = 33.33%
Therefore, the price of the sandwich has decreased by approximately 33.33%.