11 and 15 5 and 14 7 and 9 14 and 4

11 and 15 5 and 14 7 and 9 14 and 4


one hundred and sixty-five
seventy
sixty-three
twenty-eight



What is the least common multiple of 7 and 9______ What is the greatest common factor of, 15 and 12______ .


① 7 and 9 are coprime numbers, so the least common multiple is: 7 × 9 = 63. ② 12 = 2 × 2 × 315 = 3 × 5, so the greatest common factor of 12 and 15 is 3. So the answer is: 63, 3