CREATE TABLE table_26986076_6 (sat_21_aug VARCHAR2, tues_24_aug VARCHAR2)

What was the Sat 21 Aug time for the rider whose Tues 24 Aug time was 20' 38.40 109.680mph?
SELECT sat_21_aug FROM table_26986076_6 WHERE tues_24_aug = "20' 38.40 109.680mph"
SELECT "sat_21_aug" FROM "table_26986076_6" WHERE "20' 38.40 109.680mph" = "tues_24_aug"