Roberto purchased airline tickets for his family. The tickets cost $1,250. The airline also charged a luggage fee, bringing the total cost to $1,400. What is the percent increase in the cost due to the luggage fee?

The luggage fee increased the cost by $1,400 − $1,250 = $150. To find the percent increase, compare that increase with the original ticket cost: $150 ÷ $1,250 = 0.12, or 12%. So the cost increase is 12%.

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