Answer:
The correct answer is Option C.
Step-by-step explanation:
1) Simplify 9/60 to 3/20.
![(x)/(24) - (x)/(30) = (3)/(20)](https://img.qammunity.org/2022/formulas/social-studies/college/j3t29dpx325hknr85i4tapdpvc6m7kkxc5.png)
2) Simplify x/24 - x/30 to x/120.
![(x)/(120) = (3)/(20)](https://img.qammunity.org/2022/formulas/social-studies/college/9xpiqky8vu633tzbfryhi55a9byd02378f.png)
3) Multiply both sides by 120.
![x = (3)/(20) * 120](https://img.qammunity.org/2022/formulas/social-studies/college/wrxn9rxwyg92l8az2p7005vkjzvknzoh1j.png)
4) Use this rule: a/b × c = ac/b.
![x = (3 * 120)/(20)](https://img.qammunity.org/2022/formulas/social-studies/college/uz5qlctp520uabx3e5okqprdhnclaa3cia.png)
5) Simplify 3 × 120 to 360.
![x = (360)/(20)](https://img.qammunity.org/2022/formulas/social-studies/college/mxek1agjn7nszemnh3nox31ynde5at07hz.png)
6) Simplify 360/20 to 18.
![x = 18](https://img.qammunity.org/2022/formulas/mathematics/college/wsdnos4n3iai4abv7s3vgmqvnga4ji4ize.png)
Therefor, the answer is option C. 18.