CREATE TABLE table_13451 ("Position" TEXT, "Gymnast" TEXT, "A Score" FLOAT, "B Score" FLOAT, "Total" FLOAT)

what is the sum of the b score when the a score is 6.6 and the total is 15.6?
SELECT SUM("B Score") FROM table_13451 WHERE "A Score" = '6.6' AND "Total" = '15.6'
SELECT SUM("B Score") FROM "table_13451" WHERE "A Score" = '6.6' AND "Total" = '15.6'