Question

if 18x4 is divisible by 3,find the value of x

Answer 1

here the value of x could be 2 , 5 , 8 since we know that a no. is divisible by 3 when its total sum is divisible by 3. for eg. 234 . here its sum is 2+3+4=9. therefore 9 is divisible by 3 the same way in 18x4 the value of x could be 2 as 1+8+2+4=15 hence its divisible by 3 then value of x could be 5 as 1+8+5+4=18 hence its divisible by 3 then the value of x could be 8 as 1+8+8+4= 21. its also divisible by 3 and now the next value of x could be 11 but then x could only be a single digit. so here we end with the conclusion that x could be 2, 5, 8