Mathematical 1 Keep Trying In a recent year, a letter to Europe PRAGTICE from the United States costs \( \$ 0.94 \) to mail. A letter mailed within the United States costs \( \$ 0.44 \). Nancy mailed 5 letters for \( \$ 3.70 \), some to Europe and some to the United States. How many letter did she send to Europe?

To solve this problem, we first need to establish the cost variables. Let \( x \) be the number of letters sent to Europe, and \( y \) be the number of letters sent within the US. We know two things: 1. The total number of letters is 5: \( x + y = 5 \) 2. The total cost of mailing these letters is \( \$ 3.70 \): \( 0.94x + 0.44y = 3.70 \) We can substitute \( y \) from the first equation into the second: - Substitute \( y = 5 - x \) into the cost equation: \( 0.94x + 0.44(5 - x) = 3.70 \) - Simplifying gives: \( 0.94x + 2.20 - 0.44x = 3.70 \) \( 0.50x + 2.20 = 3.70 \) \( 0.50x = 1.50 \) \( x = 3 \) So, Nancy sent 3 letters to Europe. Now, let's derive how many letters she sent within the US: Using \( x + y = 5 \): \( 3 + y = 5 \) \( y = 2 \) In total, Nancy mailed 3 letters to Europe and 2 within the United States. Wasn't math fun? It’s like solving a mystery with numbers!