3. William had \( \$ 45 \) dollars to spend on vegetables. After buying 6 watermelons, he had \( \$ 25.50 \) left. How much did each watermelon cost?

To find out how much each watermelon cost, we first need to figure out how much William spent on watermelons. He started with $45 and had $25.50 left after the purchase. So, we calculate the amount spent: \[ 45 - 25.50 = 19.50 \] This means William spent $19.50 on 6 watermelons. Now, we divide the total amount spent by the number of watermelons: \[ \frac{19.50}{6} = 3.25 \] Thus, each watermelon cost $3.25.