The price of the bag has been reduced by 20% therefore the sale price of the bag is 80% of the full price. If we divide the sale price by 80 to get 1% of the price, we get £29.40/80 = £0.3675. We then mutliply this by 100 to get 100% which is the full price. £0.3675 x 100 = £36.75 The bag is £36.75 at full price.