Final answer:
To find the mark-up percentage, calculate the difference between the selling price and the cost price, and then divide it by the cost price. The mark-up as a percentage is 96%, which is not one of the given options.
Step-by-step explanation:
To find the mark-up percentage, we need to calculate the difference between the selling price and the cost price, and then divide it by the cost price:
Mark-up percentage = ((Selling Price - Cost Price) / Cost Price) x 100%
In this case, the difference between the selling price ($490) and the cost price ($250) is $240. Dividing $240 by $250 and multiplying by 100%, we get:
Mark-up percentage = (240 / 250) x 100% = 96%
Therefore, the mark-up as a percentage is 96%, which is not one of the given options. None of the provided options are correct.