Given: Let the 2 positive integers be A and B A*B = 540To Find:Which of the 3 pairs of numbers can be LCM(A,B) and GCD(A,B) respectivelyApproach: To answer the question, well evaluate the constraints on LCM(A,B) and GCD(A,B): Constraint 1: LCM(A,B) * GCD(A,B) = A*B Constraint 2: The LCM(A,B) contains the highest power EACH prime factor of A and B. This means, every prime factor that occurs in either one or both of A and B is represented in the LCM(A,B) So, every prime factor that occurs in the product of A and B will also occur in LCM(A,B) Next, well find which of the 3 pairs satisfy both the above constraintsWorking out: Evaluating the 2 constraints Constraint 1: LCM(A,B) * GCD(A,B) = 540 Constraint 2: 540 = 22 *33 *5 The prime factors of 540 are 2, 3 and 5 So, the prime factors of LCM(A,B) are 2, 3 and 5 Checking the 3 pairs 108 and 5 The product of 108 and 5 is 540. So, the first Constraint is satisfied 108 = 2 *3 The prime factors of 108 are not 2, 3 and 5. So, Constraint 2 is not satisfied So, this pair is rejected 90 and 6 The product of 90 and 6 is 540. So, the first Constraint is satisfied 90 = 2*3 *5 The prime factors of 90 are 2, 3 and 5. So, Constraint 2 is also satisfied So, this pair is possible 27 and 20 The product of 27 and 20 is 540. So, the first Constraint is satisfied 27 = 33 The prime factors of 27 are not 2, 3 and 5. So, Constraint 2 is not satisfied So, this pair is rejectedLooking at the answer choices, we see that the correct answer is Option B