I hope I'm not helping with school homework problem 
here is the script:
Code:
#!/bin/bash
OUT="/tmp/list.$$"
c=0
pos=$1 # file position
dir=$2 # directory name
[ $# -ne 2 ] && exit 1 || :
find ${dir} -type f -print > $OUT
while read line
do
(( c++ ))
if [ $c -eq $pos ];
then
echo "Deleting $line at $c pos..."
echo "/bin/rm $line"
c=0 # reset
fi
done < $OUT
/bin/rm $OUT
Call script as follows for 5th position and /tmp dir:
For 10th position and /tmp/d2 dir
Code:
./script.sh 5 /tmp/d2
Read scripting book if you need further information regarding all commands used in this script.
Good luck!