What approximate value will come in place of question mark(?) in the given question ? (You are not expected to calculate the exact value)
`2430div7.998-79.75+?^2 = 850`

Options

A. 30
B. 25
C. 9
D. 20

Answer

To find the approximate value that will come in place of the question mark (?) in the equation:

\[ 2430 \div 7.998 - 79.75 + ?^2 = 850 \]

we can follow these steps:

### Step 1: Approximate the values
First, we approximate the values in the equation.

- Approximate \( 7.998 \) to \( 8 \)
- Approximate \( 79.75 \) to \( 80 \)

So, the equation becomes:

\[ 2430 \div 8 - 80 + ?^2 = 850 \]

### Step 2: Perform the division
Now, we calculate \( 2430 \div 8 \):

\[ 2430 \div 8 = 303.75 \]

For approximation, we can round this to \( 304 \).

### Step 3: Substitute back into the equation
Now substitute back into the equation:

\[ 304 - 80 + ?^2 = 850 \]

### Step 4: Simplify the equation
Now simplify the left side:

\[ 304 - 80 = 224 \]

So the equation now is:

\[ 224 + ?^2 = 850 \]

### Step 5: Isolate \( ?^2 \)
Now, isolate \( ?^2 \):

\[ ?^2 = 850 - 224 \]

Calculating this gives:

\[ ?^2 = 626 \]

### Step 6: Find the approximate value of \( ? \)
Now, we need to find \( ? \):

\[ ? = \sqrt{626} \]

For approximation, we can use the square root of a nearby perfect square. The closest perfect square is \( 625 \):

\[ \sqrt{625} = 25 \]

Thus, we can approximate:

\[ ? \approx 25 \]

### Final Answer
The approximate value that will come in place of the question mark (?) is **25**.

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