CREATE TABLE table_41978 ("Rank" FLOAT, "Nation" CLOB, "Gold" FLOAT, "Silver" FLOAT, "Bronze" FLOAT, "Total" FLOAT)

Which Bronze has a Silver of 15, and a Gold smaller than 20?
SELECT SUM("Bronze") FROM table_41978 WHERE "Silver" = '15' AND "Gold" < '20'
SELECT SUM("Bronze") FROM "table_41978" WHERE "Gold" < '20' AND "Silver" = '15'