Evaluate: $986 \times 137 + 986 \times 863$
Aptitude
Number System
Difficulty: Easy
Choose an option
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A986000
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B98600
-
C9860000
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D985000
Answer
Correct Answer: 986000
Explanation
### Concept & Logic
This problem relies on the Distributive Property of Multiplication over Addition. The formula is $a \times b + a \times c = a \times (b + c)$. Identifying a common factor allows you to simplify complex arithmetic into simple base-10 multiplication.
### Step-by-Step Solution
* **Given:** $986 \times 137 + 986 \times 863$
* **Calculation:** Identify the common factor, which is $986$. Factor it out of the expression:
$$ 986 \times (137 + 863) $$
* Simplify the addition inside the parentheses first:
$$ 137 + 863 = 1000 $$
* Multiply by the factored number:
$$ 986 \times 1000 = 986000 $$
### Exam Strategy & Shortcut
Scan expressions for repeating numbers before doing any math. If you see the same large number being multiplied in separate terms, always factor it out. The non-common numbers (here, $137$ and $863$) are almost always designed by the examiner to sum perfectly to $10$, $100$, or $1000$.
### Common Pitfall
A strict, blind application of the BODMAS rule without looking for algebraic simplifications first will cause a student to multiply $986 \times 137$ and $986 \times 863$ separately, taking minutes instead of seconds.
### Final Answer
Therefore, the correct answer is **986000**.