The percent increase from the original cost of the entertainment system to the cost of the entertainment system using the payment plan is 12%.
Step-by-step explanation:
Percentage increase = (higher value - lower value/ lower value) [tex]\times[/tex] 100
⇒ ((560-500)/500) [tex]\times[/tex] 100
⇒ (60/500) [tex]\times[/tex] 100
⇒ 0.12 [tex]\times[/tex] 100
⇒ 12%