CREATE TABLE table_24402 ("Team name" TEXT, "Races" FLOAT, "Won" FLOAT, "RR1 Pts." FLOAT, "RR2 Pts." FLOAT, "RR3 Pts." FLOAT, "RR4 Pts." TEXT, "Total Pts." FLOAT, "Ranking" FLOAT)

When 20 is the rr4 points what is the lowest rr3 points?
SELECT MIN("RR3 Pts.") FROM table_24402 WHERE "RR4 Pts." = '20'
SELECT MIN("RR3 Pts.") FROM "table_24402" WHERE "RR4 Pts." = '20'