CREATE TABLE table_name_29 (display_size__in_ VARCHAR, model VARCHAR)

Which Display size (in) has a Model of vaio pcg-u3?
SELECT COUNT(display_size__in_) FROM table_name_29 WHERE model = "vaio pcg-u3"
SELECT COUNT("display_size__in_") FROM "table_name_29" WHERE "model" = "vaio pcg-u3"