36. Ms. Kandler buys a birthday card for \( \$ 4 \). She then buys postcards, \( p \), for \( \$ 3 \) each. Which equation shows how many postcards she must buy to spend \( \$ 46 \) total and incl the correct answer? \[ \begin{array}{ll}\text { A. } 4 p+3=46 & \text { She will buy } 10 \text { postcards } \\ \text { B. } 3 p=46 & \text { She will buy } 15 \text { postcards } \\ \text { C. } 4+3 p=46 & \text { She will buy } 14 \text { postcards } \\ \text { D. } 3 p=46 & \text { She will buy } 14 \text { postcards }\end{array} \]

To figure out how many postcards Ms. Kandler can buy within her budget, we start with the total amount she intends to spend, which is $46. She has already spent $4 on the birthday card, leaving her with $42 to spend on postcards. Since each postcard costs $3, we can set up the equation \( 4 + 3p = 46 \). This simplifies to finding the value of \( p \), which turns out to be 14, meaning she can buy 14 postcards! In mathematics, setting up the right equation is essential. A common misunderstanding is forgetting to subtract initial costs from the total amount available. Always ensure you account for all expenses before diving into calculations!