Final answer:
To find the price of a $24 shirt after a 30% discount, calculate 30% of $24 to get the discount amount, which is $7.20. Subtract this from the original price to get the final price, $16.80.
Step-by-step explanation:
The question asks what the price of a $24 shirt is after a 30% discount. To calculate the discount, you can multiply the original price by the discount percentage to find out how much money is being taken off the original price. Here, a 30% discount is the same as multiplying by 0.30 (since percentages are out of 100). So, calculate 30% of $24:
$24 × 0.30 = $7.20 (discount amount)
Now, subtract the discount amount from the original price to determine the final price:
$24 - $7.20 = $16.80
Therefore, the price of the shirt after a 30% discount is $16.80, which corresponds to option a.