Answer:
The correct answer is Option C.
Explanation:
1) Simplify 9/60 to 3/20.
[tex] \frac{x}{24} - \frac{x}{30} = \frac{3}{20} [/tex]
2) Simplify x/24 - x/30 to x/120.
[tex] \frac{x}{120} = \frac{3}{20} [/tex]
3) Multiply both sides by 120.
[tex]x = \frac{3}{20} \times 120[/tex]
4) Use this rule: a/b × c = ac/b.
[tex]x = \frac{3 \times 120}{20} [/tex]
5) Simplify 3 × 120 to 360.
[tex]x = \frac{360}{20} [/tex]
6) Simplify 360/20 to 18.
[tex]x = 18[/tex]
Therefor, the answer is option C. 18.
