To find out how much the amount of water in the canteen should change every 10 minutes, we need to divide the recommended amount of water per hour by 6 (since 60 minutes divided by 10 minutes is 6).
24 ounces / 6 = 4 ounces
Therefore, the amount of water in the canteen should change by 4 ounces every 10 minutes.
The correct answer is:
• 4 ounces