Find the least 5 digit number which when divided by 6,9,12 and 18 leaves a remainder of 3 in each case

First take the LCM of 6,9,12 and 18 

therefore, LCM of 6,9,12 and 18  = 36 

now, the number is 36x+3

put x = 1, 

the number = 39

x= 2, 

number = 75

and so on.....till

x= 278, 

number = 36(278)+3=10008+3=10011

thus, 10011 is the least 5 digit number which when divided by 6,9,12 and 18 leaves a remainder of 3 in each case.