Two successive discounts of 20% and 40% are equal to a single discount of:

💡 Solution & Explanation

Take the price as 100. After 20% off it is 80. The second discount of 40% is on 80, which is 32, leaving 48. The total reduction is 52, so the single discount is 52%. Shortcut: a + b − ab/100 = 20 + 40 − 8 = 52%. Simply adding gives 60%, which is too high.