I am a common factor of 42 and 54. I am a multiple of 3 and 6. I am greater than 5. What number am I?
Factors of 42: 1, 2, 3, 6, 7, 14, 21, 42
Factors of 54: 1, 2, 3, 6, 9, 18, 27, 54
Highest common factor of 42 and 54: 6
Multiples of 3: 3, 6
Multiples of 6: 6
Lowest common multiple of 3 and 6: 6
The number is 6.
Answer(s): 6