Find the total number of prime factors in the expression $(4)^{11} \times (7)^5 \times (11)^2$.
Aptitude
Number System
Difficulty: Easy
Choose an option
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A18
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B22
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C29
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D30
Answer
Correct Answer: 29
Explanation
### Concept & Logic
Prime factorization requires converting all composite bases in an expression into their prime factors before summing the exponents.
### Step-by-Step Solution
**Given:**
Expression: $(4)^{11} \times (7)^5 \times (11)^2$.
**Calculation / Deduction:**
* Identify the prime and composite bases. Here, $7$ and $11$ are already prime numbers, but $4$ is composite.
* Convert $4$ to its prime base: $4 = 2^2$.
* Substitute this back into the expression:
$$ (2^2)^{11} \times (7)^5 \times (11)^2 $$
* Apply the exponent rule $(a^m)^n = a^{m \times n}$:
$$ 2^{22} \times 7^5 \times 11^2 $$
* The total number of prime factors is simply the sum of these prime exponents: $22 + 5 + 2 = 29$.
### Exam Strategy & Shortcut
To find total prime factors quickly, just multiply the exponent of any composite number by the count of its prime components. Since $4 = 2 \times 2$ (two components), its exponent contribution is $11 \times 2 = 22$. Then just add the rest: $22 + 5 + 2 = 29$.
### Common Pitfall
The most common mistake is ignoring the composite base and directly adding the given exponents ($11 + 5 + 2 = 18$). Always verify that every base is a prime number before summing.
### Final Answer
Therefore, the correct answer is 29.