Set 5: Systems of Equations (Intermediate)

Choice C is correct. Choice C is the correct answer. Let $c$ be cookies and $b$ be brownies. System: $\begin{cases} c + b = 50 \\ 2 c + 3 b = 120 \end{cases}$ Step 1: I Strategic Tip: Word problems with totals naturally lead to systems of equations. Choice A is incorrect because $2(25) + 3(25) = 125 \neq 120$. Choice B is incorrect because $2(35) + 3(15) = 115 \neq 120$. Choice D is incorrect because $2(20) + 3(30) = 130 \neq 120$.