SQL> select * from test;

A B C D E
- - - - -
Y N Y N N

SQL> select length(replace(str, 'N', '')) number_of_Y,
  2         length(replace(str, 'Y', '')) number_of_N
  3  from (select a||b||c||d||e str
  4        from test
  5       );

NUMBER_OF_Y NUMBER_OF_N
----------- -----------
          2           3

SQL>