What number should replace the question mark?

752 - - - 6

687 - - - 2

693 - - - 5

426 - - - ?

Answer is 1.

The sum of the first two digits is divided by the third digit to give the number on the right. (7+5)/2=6 (6+8)/7=2 (6+9)/3=5 (4+2)/6=? ?=1

12 - - - 25

5 - - - 11

21 - - - 43

18 - - - 37

2 - - - ?