A number that is divisible by 6 will be divisible by 2and by 3. An integer is divisible by 2 if its units digit is even. An integer is divisible by 3 if the sum of its digits is divisible by 3.
__
The given number has a units digit of 9, which is <em>not even</em>. The number cannot be made divisible by 2 for any inserted digit.
Distance on a number line is basically difference between two numbers. So we subtract the two numbers. This can be solved on a calculator btw. 7/12 - √16/81 = 5/36.
