65% 35%
 
number of tables with 6 chairs:
35
number of tables with 4 chairs:

20 total tables

65% of the tables have 6 chairs at each table. in total, there are
chairs at these tables.

35% of the tables have 4 chairs at each table. in total, there are
chairs at these tables.

altogether, there is a total of
chairs in the hospital cafeteria.