Find the least common multiple of each of these pairs of numbers by the method of intersection of sets of multiples. (a) 18 and 32 (b) 14 and 11 (c) 42 and 72 (a) The LCM is (Simplify your answer.)

To find the least common multiple (LCM) using the method of intersection of sets of multiples, first list multiples of each number until you find the smallest common one. (a) For 18, the multiples are: 18, 36, 54, 72, 90, 108, 126, ... For 32, the multiples are: 32, 64, 96, 128, ... The smallest common multiple is 144. So, the LCM of 18 and 32 is **144**. (b) For 14, the multiples are: 14, 28, 42, 56, 70, 84, ... For 11, the multiples are: 11, 22, 33, 44, 55, 66, 77, ... The smallest common multiple is 154. So, the LCM of 14 and 11 is **154**. (c) For 42, the multiples are: 42, 84, 126, 168, ... For 72, the multiples are: 72, 144, 216, 288, ... The smallest common multiple is 504. So, the LCM of 42 and 72 is **504**.