How to apply 2 back to back discount modifiers on Sales Orders

How to apply 2 discount modifiers M1 and M2 which gives discount of 20% and 25% respectively to give discount like

List Price - 100

- First Apply M1 Modifier first to give 20% discount - This brings the price to = 100-(20%100) = 80

- Now, Apply M2 Modifier to give another 25% discount on discounted price = 80 - (25%80) = 60

100-->Apply 20% Discount >>80 >> Apply 25% Discount >>60