Hi there!
The percentage of the discount is 43%
To find this answer you have to butterfly multiply, in other words, you have 8.60 over 20 (20 representing the 100% of the total amount and 8.60 being the amount of the discount that has to be found). With the two over each other in a fraction form, you multiply the numerator by the 100. Then you divide that product by the denominator. In this case it would be 8.60 x 100 divided by 20. Equaling 43.
Hope this helps!