So, you need to increase it by 20%. so 20% of 120 is 120/5 = 24. add 24 to 120 = 144. the original cost of the product is $144 as it's discount makes it 20% cheaper changing to 120. thanks for your question.
Simply add 20% to 120, to get 144. $144 is your answer. Don't forget to rate 5 stars and give me the brainliest answer! Then, I can help you with all your problems! ^-^ ~