The price of a water bottle is first increased by 10% and then decreased by 10%. What is the net change in its price?

💡 Solution & Explanation

Take the price as 100. After a 10% increase it becomes 110. A 10% decrease is taken on 110, which is 11, so the price becomes 99. That is 1 less than the start: a net decrease of 1%. Shortcut: an equal rise and fall of x% always gives a decrease of x²/100 %.