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How many prime factors, counted with repetition, does 21252 = 2^2 x 3 x 7 x 11 x 23 have?
ASix
BFour
CFive
DSeven
Answer & Solution
Correct answer: A. Six
1. Counting with repetition means each prime is counted as many times as it appears.
2. The factor 2^2 contributes two primes.
3. The factors 3, 7, 11 and 23 contribute one each, so four more.
4. The total is 2 + 4 = 6.
5. Answering four would be counting distinct primes only, which is the trap here.
_Source: NCERT Class 10 Maths, Ch 1 'Real Numbers', S1.2 The Fundamental Theorem of Arithmetic_
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