What approximate value will come in place of questions mark (?) in the given questions? (You are not expected to calculate the exact value.)
`(31.94)/(1.98^3)+(42.04)/?=7`

Options

A. 21
B. 7
C. 14
D. 18

Answer

To solve the equation `(31.94)/(1.98^3) + (42.04)/? = 7`, we will approximate the values to make the calculations easier.

### Step-by-Step Solution:

1. **Approximate the values**:
- Round `31.94` to `32`.
- Round `1.98` to `2`.
- Round `42.04` to `42`.

So the equation now looks like:
\[ \frac{32}{2^3} + \frac{42}{?} = 7 \]

2. **Calculate \(2^3\)**:
\[ 2^3 = 8 \]
Therefore, the equation simplifies to:
\[ \frac{32}{8} + \frac{42}{?} = 7 \]

3. **Calculate \(\frac{32}{8}\)**:
\[ \frac{32}{8} = 4 \]
Now the equation becomes:
\[ 4 + \frac{42}{?} = 7 \]

4. **Isolate \(\frac{42}{?}\)**:
Subtract `4` from both sides:
\[ \frac{42}{?} = 7 - 4 \]
\[ \frac{42}{?} = 3 \]

5. **Solve for \(?\)**:
To find the value of `?`, we can rearrange the equation:
\[ ? = \frac{42}{3} \]

6. **Calculate \(\frac{42}{3}\)**:
\[ \frac{42}{3} = 14 \]

Thus, the approximate value that will come in place of the question mark (?) is **14**.