A) AP
B) GP
C) HP
D) none of these
Correct Answer: A
Solution :
Key-Idea: If a, b and c are the prime numbers, then the divisors of\[{{a}^{{{n}_{1}}}}{{b}^{{{n}_{1}}}}{{c}^{{{n}_{3}}}}\]is \[({{n}_{1}}+1)({{n}_{2}}+1)({{n}_{3}}+1)\] The number of divisors of \[3\times {{7}^{3}}=8,\] the number of divisors of \[7\times {{11}^{2}}=6\]and the number of divisors of \[2\times 61=4\] \[\Rightarrow 8,6,4\]are in AP with common difference \[-2.\]
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