CREATE TABLE table_10506 ("Driver" TEXT, "Constructor" TEXT, "Laps" FLOAT, "Time/Retired" TEXT, "Grid" FLOAT)

What is the time/retired for jo siffert with a grid under 11?
SELECT "Time/Retired" FROM table_10506 WHERE "Grid" < '11' AND "Driver" = 'jo siffert'
SELECT "Time/Retired" FROM "table_10506" WHERE "Driver" = 'jo siffert' AND "Grid" < '11'