Final answer:
The original price of the couch was $800, computed by dividing the sale price of $600 by 0.75 since the couch was marked down by 25%.
Step-by-step explanation:
To find the original price of the couch, we need to recognize that the sale price represents 75% of the original price because the couch has been marked down by 25%. Therefore, if $600 represents 75%, we can find the original price by setting up the following equation:
Original Price × (1 - 0.25) = Sale Price
Original Price × 0.75 = $600
Now, dividing both sides by 0.75 gives us the original price:
Original Price = $600 ÷ 0.75
Original Price = $800
Therefore, the original price of the couch was $800.