What is the lap total for the grid under 15 that retired due to transmission?
CREATE TABLE table_56490 (
    "Driver" text,
    "Constructor" text,
    "Laps" real,
    "Time/Retired" text,
    "Grid" real
)
SELECT SUM("Laps") FROM table_56490 WHERE "Grid" < '15' AND "Time/Retired" = 'transmission'
Below are sql tables schemas paired with instruction that describes a task. Using valid SQLite, write a response that appropriately completes the request for the provided tables. ### Instruction: What is the lap total for the grid under 15 that retired due to transmission? ### Input: CREATE TABLE table_56490 (
    "Driver" text,
    "Constructor" text,
    "Laps" real,
    "Time/Retired" text,
    "Grid" real
) ### Response: SELECT SUM("Laps") FROM table_56490 WHERE "Grid" < '15' AND "Time/Retired" = 'transmission'