To determine if Mario has enough money to buy the notebook, follow these steps:1. **Calculate the total amount of money Mario has:** - He has one 5-peso coin. - He has twenty 25-centavo coins.2. **Convert the 25-centavo coins to pesos:** Each 25-centavo coin is worth 0.25 pesos. So, for twenty coins: \[ 20 \times 0.25 = 5 \text{ pesos} \]3. **Add the value of the 5-peso coin:** Total money: \[ 5 \text{ pesos (from the coin)} + 5 \text{ pesos (from the 25-centavo coins)} = 10 \text{ pesos} \]4. **Compare the total amount with the cost of the notebook:** The notebook costs 12 pesos. Mario has only 10 pesos.**Conclusion:** Mario does not have enough money to buy the notebook. He needs 2 more pesos.