Final answer:
To find the average rate of selling ice cream in the fifth hour, divide the average number of ice creams sold per hour by the total number of hours.
Step-by-step explanation:
To find the average rate of selling ice cream in the fifth hour, we need to calculate the average number of ice creams sold per hour and then divide that by the total number of hours. Since the ice cream truck sells ice cream between 2pm and 10pm, there are a total of 8 hours. Let's say that on average, the ice cream truck sells 200 ice creams per hour. To find the average rate in the fifth hour, we divide 200 by 8 to get 25 ice creams. Therefore, the average rate of selling ice cream in the fifth hour is 25 ice creams.