CREATE TABLE table_15187735_20 (segment_c VARCHAR2, segment_d VARCHAR2)

How many segment C are there in the episode where segment D is bicycle tires?
SELECT COUNT(segment_c) FROM table_15187735_20 WHERE segment_d = "Bicycle Tires"
SELECT COUNT("segment_c") FROM "table_15187735_20" WHERE "Bicycle Tires" = "segment_d"