Confused About Salary Calculation: Should We Divide by 26 or 30 Days?

Dear sir,

If an employee's basic salary is 10,000 and DA is 1,000, and the paid days are 15, what would be the gross salary and PF amount? Please suggest to me about this.

Additionally, there is another problem: should we divide the salary by 26 or 30? Please provide a specific reason for your suggestion.

Thank you.

Salary is monthly inclusive of Sundays, divided by 30.

Wages are calculated daily by multiplying the daily wages by 26, or monthly wages divided by 26 multiplied by the number of days worked. No work, no pay; no pay for weekly off.