what is the sum of digits of the least number which when divided by 15 18 24 leaves a remainder 8 in each case and also divided by 13

LCM of 15,18, 24 = 360 So the number is of the form 360k+8 This number is also divisible by 13. When k=1 i.e. 368 is not divisible by 13 When k=2 i.e. 728 is divisible by 13. Hence 728 is the answer!