FEEL FREE TO ASK DOUBTS- Q. How to find LCM of 72,180,360 Ans : There are three methods to Find LCM - FACTOR TREE METHOD PRIME FACTORISATION METHOD DIVISION METHOD 1. Factor Tree Method : 72 2* 36 2* 2* 18 2* 2* 2*9 2* 2* 2* 3*3 180 2*90 2*2*45 2*2*3*15 2*2*3*3*3*5 360 2*180 2*2*90 2*2*2*45 2*2*2*3*15 2*2*2*3*3*5 So LCM is least common multiple which is 2*2*2*3*3**5 =360 (Here We write all common factors & rest factors both) 2. Prime Factorisation method : [ 72 ]= 2 | 72 2 | 36 2 | 18 3 | 9 3 | 3 | 1 = 2*2*2*3*3 [180]= 2 | 180 2 | 90 3 | 45 3 | 15 5 | 5 | 1 = 2*2*3*3*5 [360]= 2 | 360 2 | 180 2 | 90 3 | 45 3 | 15 5 | 5 | 1 = 2*2*2*3*3*5 So LCM = 2*22*3*3*5 = 360 3. Division method of LCM 2 | 72 , 180 , 360 2 | 36 , 90 , 180 2 | 18 , 45 , 90 3 | 9 , 15 , 45 3 | 3 , 5 , 15 5 | 1 , 5 , 5 | 1 , 1 , 1 So LCM...