To find out how many dirty coffee mugs there are at Brenna's Pancake House, we can calculate 72% of 75 coffee mugs.
First, convert the percentage to a decimal: \[ 72% = \frac{72}{100} = 0.72 \]
Next, multiply this decimal by the total number of coffee mugs: \[ 0.72 \times 75 \]
Now, perform the multiplication: \[ 0.72 \times 75 = 54 \]
Therefore, there are 54 dirty coffee mugs at Brenna's Pancake House.