`30% of ? = 312-216`

Options

A. 320
B. 420
C. 380
D. 1318

Answer

To solve the equation \(30\% \text{ of } ? = 312 - 216\), we will follow these steps:

### Step 1: Calculate the right side of the equation
First, we need to calculate \(312 - 216\).

\[ 312 - 216 = 96 \]

### Step 2: Set up the equation
Now, we can rewrite the equation using the result from Step 1:

\[ 30\% \text{ of } ? = 96 \]

### Step 3: Convert percentage to a fraction
Next, we convert \(30\%\) to a fraction.

\[ 30\% = \frac{30}{100} = \frac{3}{10} \]

So we can rewrite the equation as:

\[ \frac{3}{10} \times ? = 96 \]

### Step 4: Isolate the variable
To isolate \(?\), we can multiply both sides of the equation by the reciprocal of \(\frac{3}{10}\), which is \(\frac{10}{3}\):

\[ ? = 96 \times \frac{10}{3} \]

### Step 5: Perform the multiplication
Now we calculate \(96 \times \frac{10}{3}\):

\[ ? = \frac{96 \times 10}{3} = \frac{960}{3} \]

### Step 6: Simplify the fraction
Now we divide \(960\) by \(3\):

\[ 960 \div 3 = 320 \]

### Final Answer
Thus, the value of \(?\) is:

\[ ? = 320 \]