Evaluate: $983 \times 207 - 983 \times 107$
Aptitude
Number System
Difficulty: Easy
Choose an option
-
A9830
-
B97300
-
C983000
-
D98300
Answer
Correct Answer: 98300
Explanation
### Concept & Logic
This question tests the Distributive Property of Multiplication over Subtraction, represented by the formula $a \times b - a \times c = a \times (b - c)$. By factoring out the common multiplier, you turn a tedious calculation into mental math.
### Step-by-Step Solution
* **Given:** $983 \times 207 - 983 \times 107$
* **Calculation:** Extract the common multiplier, $983$:
$$ 983 \times (207 - 107) $$
* Perform the subtraction inside the parentheses:
$$ 207 - 107 = 100 $$
* Multiply the common factor by the result:
$$ 983 \times 100 = 98300 $$
### Exam Strategy & Shortcut
Just like with addition, look for identical numbers separated by a minus sign. Factor out the $983$, and quickly subtract the remaining terms ($207 - 107 = 100$). Simply add two zeros to $983$ to arrive at the answer instantly.
### Common Pitfall
Failing to spot the common factor and attempting to brute-force the multiplication of both terms individually. Examiners specifically write these numbers so that their difference is a neat power of 10 to reward students who check for patterns first.
### Final Answer
Therefore, the correct answer is **98300**.