Answer:
Region C
Step-by-step explanation:
y ≤ ¼ x + 3 maps the areas C and D including the common boundary line
y ≥ -x + 5 maps the areas B and C including the common boundary line
The common area mapped is C plus its boundaries
Step 1: Set up the proportion
4/12 = 10/x
Step 2: Cross multiply to get
120 = 4x
Step 3: Divide all by 4 to get
30 = x
Answer: So in total, 10 students would spend $30 on lunch!