CREATE TABLE table_64894 ("Size" TEXT, "Density" TEXT, "Tracks" FLOAT, "Coercivity" TEXT, "Unformatted capacity per side" TEXT)

How many tracks have a single density?
SELECT COUNT("Tracks") FROM table_64894 WHERE "Density" = 'single'
SELECT COUNT("Tracks") FROM "table_64894" WHERE "Density" = 'single'