.
Show that for any positive rational numbers a/b and c/d if a/b is less than c/d then a/d is less than c/b
~~~~~~~~~~~~~~~~~~
This statement is INCORRECT.
According to your statement, if we start from the correct statement
< with a= 2, b= 3, c= 1 and d= 1
then we come to the inequality
< ,
which is wrong.
Say, where did you get (retrieve) such a GIBBERISH ? ? ? ? ? ?