The number 0.7142857 is definitely a rational number. This number
can also be expressed as 7142857/10000000. Now we know that a rational number
is a number that can be expressed as a fraction or a quotient of two integers.
The denominator of the fraction can never be equal to zero. In case of the
number given we can clearly see that the denominator of this fraction is not
zero. The actual fraction of this number is 5/7. In this case we find that the
denominator is not zero.
