Mani Grover

Hello I have 2 venn digrams please checke the attached file for pictures of venn diagram for eg red is A yellow is B and green is C In one ..... I have 3 data set A B and C Venn diagram between A and B shows: A = 13+2098 B =2098+27079 now in venn diagram between A and B there are 2098 common entries but in venn diagram between A B and C:there are only 2097 entries common in A and B(including those whichare common between A , B and C is there somethign wrong why its happening?pease explain