Molly bought a pair of jeans on sale for $\$ 40.00$. If the jeans were on sale for $20 \%$ off of the retail price, what was the original retail price? \[ \$ \] Preview

Step 1 ：The original price of the jeans can be calculated by dividing the sale price by the percentage of the original price that the sale price represents. In this case, the sale price represents 80% of the original price (100% - 20%), so we divide the sale price by 0.8 to find the original price.

Step 2 ：Let the sale price be \( \$40.00 \) and the discount be \( 20\% \) or \( 0.2 \).

Step 3 ：The original price can be calculated as \( \frac{sale\_price}{1-discount} \).

Step 4 ：Substituting the given values, we get \( \frac{40}{1-0.2} = \$50.00 \).

Step 5 ：Final Answer: The original retail price of the jeans was \(\boxed{\$50.00}\).