Multiple choice general knowledge math & puzzles 4 , 3 , 7 ; 5 , 6 , 11 ; 16 , 5 , 21; 12 , 4 , ? 16 33 48 11 Reveal answer Fill a bubble to check yourself A Correct answer Explanation In each triplet, the third number is the sum of the first two. 4+3=7, 5+6=11, 16+5=21. Therefore 12+4=16.