3. A new concrete courtyard will be 15 feet by 25 feet and will be filled to a depth of 3 inches (1/4 foot). How much concrete do you need?

Step 1 ：1. Calculate the volume: V = length \times width \times depth

Step 2 ：2. Substitute the given values: V = 15 \times 25 \times \frac{1}{4}

Step 3 ：3. Calculate V: V = 93.75 cubic feet