Multiple choice Which of the following is the L.C.M of the numbers 15 and 20? 120 45 60 40 35 Reveal answer Fill a bubble to check yourself C Correct answer Explanation Multiples of 15 = {15, 30, 45, 60, 75, 90, 105, 120...} Multiples of 20 = {20, 40, 60, 80, 100, 120...} Common multiples of 15 & 20 = {60, 120...} Lowest Common Multiple (L.C.M) = smallest element of the set {60, 120...} = 60