Question

find the least number which divided by 6,15and 18leave reminder5in each case?

Answer 1

L.C.M OF 6,15,18 IS 90.
 90+5=95
95 is the least  dividend when divided by 6,15,18 by giving ramainder 5. 

Answer 2

You have to find LCM of the three numbers
6 = 2*3
16 = 3*5
18 = 2*3²
LCM = 2*3²*5 = 90
It should leave remainder 5, so add 5 to LCM

∴ Number is 90+5 = 95