Some questions are solved on the basis of a certain system. On the same basis, find out the correct answer from amongst the four alternatives for the unsolved equation in each question.
16 (210) 14, 14 (156) 12, 12 (?)10 `A. 110` `B. 100` `C. 120` `D. 90`

Options

A. 110
B. 100
C. 120
D. 90

Explanation

To solve the given equation step by step, let's analyze the pattern from the previous equations:

### Given Equations:
1. **16 (210) 14**
2. **14 (156) 12**
3. **12 (?) 10**

### Step 1: Identify the Pattern
From the first equation, we can see:
- Multiply the first number (16) by the last number (14):
\[ 16 \times 14 = 224 \]
- Then, subtract the last number (14) from this product:
\[ 224 - 14 = 210 \]
This confirms that the equation holds true.

### Step 2: Verify the Second Equation
Now, let's check the second equation:
- Multiply the first number (14) by the last number (12):
\[ 14 \times 12 = 168 \]
- Then, subtract the last number (12) from this product:
\[ 168 - 12 = 156 \]
This also confirms that the equation holds true.

### Step 3: Apply the Pattern to the Third Equation
Now, we need to solve for the unknown in the third equation:
- Multiply the first number (12) by the last number (10):
\[ 12 \times 10 = 120 \]
- Then, subtract the last number (10) from this product:
\[ 120 - 10 = 110 \]

### Conclusion
The value that replaces the question mark (?) is:
\[ \text{Answer: } 110 \]

### Final Answer
The correct option is **A. 110**.

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