The average salary of the entire staff in Reliance Company is Rs.15000 per month. The average salary of officers is Rs.45000 per month and that of non-officers is Rs.10000 per month. If the number of officers is 20 then find the number of non-officers in the Reliance company. রিলায়েন্স কোম্পানির সমস্ত কর্মচারীর গড় মাসিক বেতন Rs.15000। অফিসারদের গড় বেতন Rs.45000 এবং নন-অফিসারদের গড় বেতন Rs.10000। যদি অফিসারের সংখ্যা 20 হয়, তবে অফিসার নয় এমন কর্মচারীর সংখ্যা কত?

Average salary of entire staff = Rs.15000

Average salary of officers = Rs.45000

Average salary of non-officers = Rs.10000

Number of officers = 20

Let number of non-officers = x

Total salary of officers:

\[ 20 \times 45000 = 900000 \]

Total salary of non-officers:

\[ 10000x \]

Total staff = \( 20 + x \)

Using average formula:

\[ \frac{900000 + 10000x}{20 + x} = 15000 \]

\[ 900000 + 10000x = 15000(20 + x) \]

\[ 900000 + 10000x = 300000 + 15000x \]

\[ 600000 = 5000x \]

\[ x = 120 \]

Number of non-officers = 120

Correct Answer: Option B