Number(A OR B OR C)
=NUMBER(A) + NUMBER(B) + Number(C) - Number(A AND B) - Number(A OR C) - Number(B AND C) + Number(A AND B AND C)
= 34+24+28 - 3 - 3 - 5 + 1
= 76
So 24 are not accounted for, they must have used none of the above
You could also use Venn diagrams