UPSC CDS 2 2021 Math Paper

Let the person work for x days.
∴ Number of days he does not work =30−x
Salary he gets for working x days =₹x×500=₹500x
Fine for the day he does not work =₹100(30−x)
Now, according to the question,
‌500x−100(30−x)=11400
⇒‌500x−3000+100x=11400
⇒‌600x=11400+3000
⇒‌600x=14400
⇒‌x=‌

14400

600

=‌

144

6

=24
Hence, the person worked for 24 days.