1. The problem asks us to find which box of pens has the cheapest cost per pen. 2. We calculate the cost per pen for each box by dividing the total cost by the number of pens: - Box of 25: $\frac{7.19}{25} = 0.2876$ - Box of 50: $\frac{10.78}{50} = 0.2156$ - Box of 75: $\frac{14.53}{75} = 0.1937$ - Box of 100: $\frac{22.50}{100} = 0.225$ - Box of 125: $\frac{26.25}{125} = 0.21$ 3. Comparing these values, the cheapest cost per pen is $0.1937$ from the box of 75 pens. 4. Therefore, the box of 75 pens has the cheapest per pen cost.