The question reads:

"If 12 oranges cost $6, how much do 30 oranges cost?"

Solution:

This is a problem of direct proportionality. Let us calculate step by step:

1. Cost per orange: $\text{Cost per orange} = \frac{\text{Total cost}}{\text{Number of oranges}} = \frac{6}{12} = 0.5 \, \text{(dollars per orange)}.$

2. Cost of 30 oranges: $\text{Cost for 30 oranges} = \text{Cost per orange} \times 30 = 0.5 \times 30 = 15 \, \text{dollars}.$

Final Answer:

The cost of 30 oranges is $15.

Would you like further details or have any questions about this problem?

Related Questions:

1. What would the cost of 20 oranges be in the same situation?
2. If 8 oranges cost $4, how much would 18 oranges cost?
3. If you have $10, how many oranges could you buy at the same rate?
4. If the price of 1 orange increases to $0.75, what is the cost of 30 oranges now?
5. How would you calculate the cost if the price per orange is given in cents?

Tip:

When solving proportion problems, always calculate the unit rate (e.g., price per item) first—it simplifies the process!