Final answer:
To calculate the total cost after the markup rate, add the markup to the original prices of the hat and shirt. The new price of the hat after the markup is $32.50, and the new price of the shirt is $52. Therefore, the total amount the customer would pay for both items is $84.50.
Step-by-step explanation:
To calculate the total cost of the items after the markup rate, we need to add the markup to the original prices of the hat and shirt. The markup rate is 30%, which means the prices will increase by 30%. For the hat, the markup is 30% of $25, which is $7.50. So the new price of the hat after the markup is $25 + $7.50 = $32.50. Similarly, the markup for the shirt is 30% of $40, which is $12. The new price after the markup is $40 + $12 = $52.
Therefore, if a customer bought both items after the markup rate, they would pay $32.50 for the hat and $52 for the shirt. Adding these prices together, the total amount they would pay is $32.50 + $52 = $84.50.