दो अभाज्य संख्याओं a और b (a>b) का लघुत्तम समापवर्तक 391 है, तब 3b - 2a किसके द्वारा विभाज्य है ?

Correct Answer: (A) 5

Since $a$ and $b$ are prime numbers with $a > b$, their LCM is simply their product: $a$$\times$ b = 391. Factoring 391 into primes gives $391 = 23$$\times$ 17, so $a = 23$ and $b = 17$. Evaluating $3b - 2a$ yields $3(17) - 2(23) = 51 - 46 = 5$.