x+y=z In the addition problem above, each of the symbols x ,y and represents a positive digit. If x < y , what is the value of Δ ? (1) z= 4 (2) x=1 OA is A but my answer is C since 0 is also a positive no and 1st statement gives two possibilities for (x,y)= (0,4) and (1,3) Is zero a positive number This question is from...