A shirt is on sale for 30% off. The sale price is $51.50. What was the orginail price?

The original price would be 171.7 $

The answer is $329.00

To contract an original price from a sale price, use:

Original price - Original Price*Mark-down percent = Sale Price, or

Original price - Original price * (Mark-down precent) = sale price

To do a do a double mark-down problem, we must do this twice for the 10%:

Original Sale Price * (1-10%) = $207.27

Original Sale Price = $207.27/0.9 = 230.30.

For the pre-sale discount price.

Original Price * (1-30%) = $230.30

Original Price = 230.30/0.7 = $329.00