The markdown price of a computer game was $45.00, which represented 75% of the original selling price. What was the original selling price?

0.75x = 45

To find the original selling price, you can set up an algebraic equation. Let's denote the original price as "x".

According to the information given, the markdown price is $45.00, which represents 75% (or 0.75) of the original selling price.

So, the equation can be written as:
0.75x = $45.00

To solve for x, divide both sides of the equation by 0.75:
x = $45.00 / 0.75

Evaluating the right side of the equation:
x = $60.00

Therefore, the original selling price of the computer game was $60.00.