I believe C/12=pi which means the answer would be B.
Best choice for variables.....I would let students be " s " and parents be " p "
Answer:

General Formulas and Concepts:
<u>Pre-Algebra</u>
Order of Operations: BPEMDAS
- Brackets
- Parenthesis
- Exponents
- Multiplication
- Division
- Addition
- Subtraction
<u>Algebra I</u>
- Terms/Coefficients
- Factoring
Step-by-step explanation:
<u>Step 1: Define</u>

<u>Step 2: Simplify</u>
- [Fraction] Factor numerator:

- [Fraction] Factor denominator:

- [Fraction] Divide:

18 x
--- = ----
5 100
18×100 = 5×x
1800 = 5x
------- ----
5 5
360 = x
Hope this helps!!!