TASK #1 - 10001st Prime Number

Write a script to generate the 10001st prime number.

(Remember that 2 is the 1st prime number).


MY NOTES: Very easy, especially (tada) if you happen to have a prime
generating module that you've already used several times in these
challenges..


TASK #2 - Curious Fraction Tree

Consider the following Curious Fraction Tree:

[diagram in which the root is 1/1, and for each element N/D
it's right child is N+D/D, and it's left child is N/N+D]

You are given a N/D member of the tree created similar to the above sample.

Write a script to find out the parent and grandparent of the given member.

Example 1:

    Input: $member = '3/5';
    Output: parent = '3/2' and grandparent = '1/2'

Example 2:

    Input: $member = '4/3';
    Output: parent = '1/3' and grandparent = '1/2'

MY NOTES: hmm..  having determined the left and right child rules
above, I worked out that given a child N/D the parent rule is
"if D>N then (N, D-N) else (N-D, D)"

So very easy using that rule twice (and why not go all the way up to
the root while we're doing it).