Two successive discounts of 50% and 20% are equal to a single discount of:

💡 Solution & Explanation

Take the price as 100. After 50% off it is 50. The second discount of 20% is on 50, which is 10, leaving 40. The total reduction is 60, so the single discount is 60%. Shortcut: a + b − ab/100 = 50 + 20 − 10 = 60%. Simply adding gives 70%, which is too high.