In an Entrance Examination Ritu scored 56 percent marks, Smita scored 92 percent marks and Rina scored 634 marks. The maximum marks of the examination are 875. What are the average marks scored by all the three girls together ?

Options

A. 1929
B. 815
C. 690
D. 643

Answer

To find the average marks scored by Ritu, Smita, and Rina, we will follow these steps:

### Step 1: Calculate Ritu's Marks
Ritu scored 56% of the maximum marks. The maximum marks are 875.

\[ \text{Ritu's Marks} = \frac{56}{100} \times 875 \]

Calculating this:

\[ \text{Ritu's Marks} = 0.56 \times 875 = 490 \]

### Step 2: Calculate Smita's Marks
Smita scored 92% of the maximum marks.

\[ \text{Smita's Marks} = \frac{92}{100} \times 875 \]

Calculating this:

\[ \text{Smita's Marks} = 0.92 \times 875 = 805 \]

### Step 3: Use Rina's Marks
Rina's marks are given directly as 634.

### Step 4: Calculate Total Marks
Now, we will sum the marks of all three girls:

\[ \text{Total Marks} = \text{Ritu's Marks} + \text{Smita's Marks} + \text{Rina's Marks} \]

Substituting the values:

\[ \text{Total Marks} = 490 + 805 + 634 = 1929 \]

### Step 5: Calculate Average Marks
To find the average marks, we divide the total marks by the number of girls (which is 3):

\[ \text{Average Marks} = \frac{\text{Total Marks}}{3} \]

Calculating this:

\[ \text{Average Marks} = \frac{1929}{3} = 643 \]

### Final Answer
The average marks scored by Ritu, Smita, and Rina together is **643**.

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