Final answer:
To find the discount percent, calculate the difference between the original price and the selling price, divide that by the original price, and multiply by 100. The discount percent is 15%.
Step-by-step explanation:
To find the discount percent, we need to calculate the amount of discount first. The discount is the difference between the original price (MP) and the selling price (SP). In this case, the discount is Rs 1200 - Rs 1020 = Rs 180.
The discount percent can be calculated by dividing the discount amount by the original price and multiplying by 100. So, the discount percent is (180 / 1200) * 100 = 15.
Therefore, the discount percent is 15%.