To determine the cost of 24 items at the rate of 4 items for 30 cents, follow these steps:

1. Determine the cost per item: $\text{Cost per item} = \frac{30 \text{ cents}}{4 \text{ items}} = 7.5 \text{ cents per item}$

2. Calculate the total cost for 24 items: $\text{Total cost} = 24 \text{ items} \times 7.5 \text{ cents per item} = 180 \text{ cents}$

3. Convert the total cost to dollars (if needed): $180 \text{ cents} = \frac{180}{100} \text{ dollars} = 1.80 \text{ dollars}$

So, the cost of 24 items is 180 cents or $1.80.

Would you like more details or have any questions?

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Here are some related questions for further exploration:

1. How much would 36 items cost at the same rate?
2. If the rate changes to 5 items for 40 cents, what would be the cost of 24 items?
3. How many items can be bought with $2.50 at the rate of 4 items for 30 cents?
4. What would be the cost of 50 items at this rate?
5. How much would 10 items cost at this rate?

Tip: Always check if the problem involves converting units (like cents to dollars) and use proportional reasoning to solve similar problems.