Answer:
A shop owner offered a 20% discount. The regular price of the item is $ 15
Solution:
Let the regular price of the mirror be taken as x
The percentage discount offered on the mirror, as given in the question, is equal to 20%
The discount amount (D) as mentioned in the question is $3
Discount amount is given as:
![\begin{array}{l}{D * 100=20 \% \text { of } x} \\\\ {D=(20)/(100) *(x)} \\\\ {3=(20)/(100) *(x)} \\\\ {x=(3 * 100)/(20)} \\\\ {x=15}\end{array}](https://img.qammunity.org/2020/formulas/mathematics/middle-school/piq99bau8io5dju42765jt915rwdhfiqxq.png)
Thus, the original cost of the mirror is x = 15 and after discount the price would have been 15 -3 = 12
Thus the regular price of the item is $ 15