The average salary of 20 workers in an office is Rs1900 per month. If the manager's salary is added, the average becomes Rs. 2000 per month. The manager's annual salary (in Rs) is:

Options

A. Rs. 24000
B. Rs. 25200
C. Rs. 45600
D. Rs. 48000

Answer

To find the manager's annual salary based on the information provided, we can follow these steps:

### Step 1: Calculate the total salary of the 20 workers.
The average salary of the 20 workers is Rs 1900 per month. To find the total salary of these workers, we can use the formula:

\[ \text{Total Salary of Workers} = \text{Average Salary} \times \text{Number of Workers} \]

Substituting the values:

\[ \text{Total Salary of Workers} = 1900 \times 20 = 38000 \text{ Rs} \]

### Step 2: Calculate the new total salary when the manager is included.
When the manager's salary is added, the average salary becomes Rs 2000 per month for 21 people (20 workers + 1 manager). We can find the new total salary using the formula:

\[ \text{New Total Salary} = \text{New Average Salary} \times \text{Total Number of People} \]

Substituting the values:

\[ \text{New Total Salary} = 2000 \times 21 = 42000 \text{ Rs} \]

### Step 3: Find the manager's salary.
To find the manager's salary, we can subtract the total salary of the workers from the new total salary:

\[ \text{Manager's Salary} = \text{New Total Salary} - \text{Total Salary of Workers} \]

Substituting the values:

\[ \text{Manager's Salary} = 42000 - 38000 = 4000 \text{ Rs (per month)} \]

### Step 4: Calculate the manager's annual salary.
To find the annual salary of the manager, we multiply the monthly salary by 12:

\[ \text{Manager's Annual Salary} = \text{Manager's Monthly Salary} \times 12 \]

Substituting the values:

\[ \text{Manager's Annual Salary} = 4000 \times 12 = 48000 \text{ Rs} \]

Thus, the manager's annual salary is Rs 48,000.

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