Final answer:
The original price of the shirt was $60, calculated by dividing the sale price of $48 by 0.80, which represents the remaining 80% of the original price after a 20% discount.
Step-by-step explanation:
The original price of an item before a discount can be calculated by dividing the sale price by the percentage that represents the remaining amount after the discount. In this case, a shirt is on sale for $48 after a 20% discount. Therefore, the sale price represents 80% of the original price, because 100% - 20% = 80%. To find the original price, we divide the sale price by 0.80 (which is 80% expressed as a decimal).
Let's calculate the original price:
Original Price = Sale Price / 0.80
Original Price = $48 / 0.80
Original Price = $60
Thus, the original price of the shirt was $60.