Listen to 3 X 7 = 21 online. 3 X 7 = 21 is an English language song and is sung by Jewel King. 3 X 7 = 21, from the album Jumping the Shuffle Blues: Jamaican Sound System Classics 1946-1960, was released in the year 2011. The duration of the song is 2:37. Download English songs online from JioSaavn.