SOLUTION: When fractions are expressed in different bases, they can be terminating or repeating. For example, when $\frac{1}{5}$ is expressed in base $3,$ the result is \[0.\overline{0121}

Algebra ->  Decimal-numbers -> SOLUTION: When fractions are expressed in different bases, they can be terminating or repeating. For example, when $\frac{1}{5}$ is expressed in base $3,$ the result is \[0.\overline{0121}      Log On


   



Question 1207598: When fractions are expressed in different bases, they can be terminating or repeating. For example, when $\frac{1}{5}$ is expressed in base $3,$ the result is
\[0.\overline{0121}_3 = 0.01210121 \dots,\]
which is repeating.
When $\frac{1}{288}$ is expressed in base $13,$ is it terminating or repeating?

Found 2 solutions by greenestamps, ikleyn:
Answer by greenestamps(13200) About Me  (Show Source):
You can put this solution on YOUR website!


The fraction 1/n, when expressed in base b, will terminate if and only if the prime factorization of n contains only factors that are prime factors of the base b.

For example, in our familiar base 10 system, since the prime factorization of 10 is 2*5, a fraction 1/n will terminate if and only if the prime factorization of n contains only 2's and 5's.

In your example, the base 13 is a prime number, so 1/n expressed in base 13 will terminate if and only if the prime factorization of n contains only 13's -- i.e., if and only if n is a power of 13.

288 is not a power of 13, so 1/288 expressed in base 13 will not terminate.

ANSWER: Repeating


Answer by ikleyn(52781) About Me  (Show Source):
You can put this solution on YOUR website!
.

If in the fraction  p%2Fq  the denominator is relatively prime to the base  b,
then this fraction  p%2Fq  in base  b  is repeating.

This general rule is  ALWAYS  valid.


Apply it in your case.  The fraction  1%2F288  has the denominator  288  relatively prime to the base  13.

THEREFORE,  the given fraction in the given base is repeating.


Solved,  answered and explained.