Accurate Explanation: Aloha! Basically, as I can see here, you're missing a slope. But you need at least 1 point and a slope in order to write an equation. Hope it helps.
For this case what you must do is the following rule of three: 50 ---> 100 80 ----> x We clear x: x = (80/50) * (100) x = 160% 160-100 = 60% Answer: toni added 60% of the original value for his sale price