To find the average cost of an apple, we need to calculate the total cost of all the apples and divide it by the total number of apples Joe bought.

1. Joe bought 3 apples at 24¢ each: $\text{Cost of 3 apples} = 3 \times 24 = 72 \text{ cents}$

2. Joe also bought 5 apples for 96¢: $\text{Cost of 5 apples} = 96 \text{ cents}$

3. The total cost of all the apples is: $72 + 96 = 168 \text{ cents}$

4. The total number of apples is: $3 + 5 = 8 \text{ apples}$

5. The average cost of one apple is: $\frac{168 \text{ cents}}{8 \text{ apples}} = 21 \text{ cents per apple}$

So, the average cost of an apple is 21 cents.

Would you like more details or have any other questions?

Here are some related questions you might explore:

1. What would the average cost be if Joe bought another apple for 30¢?
2. How would the total cost change if Joe got a discount of 10% on the 5-pack of apples?
3. What is the total weight of the apples if each apple weighs 150 grams?
4. If Joe buys 10 more apples at 25¢ each, what will be the new average cost?
5. How would the average cost change if sales tax of 5% is added to both purchases?

Tip: When calculating averages, always sum the total cost and divide by the total number of items for an accurate result.