. Human blood can be classified into types A, B, AB or O. Furthermore, each of these types is classified as positive or negative, depending on whether the antigen called Rh is present. A have the A antigen B have the B antigen Rh have the Rh antigen A hospital reports the following data:

60 patients have A antigen

50 patients have B antigen

65 patients have Rh antigen

15 patients have both the A & B antigens

20 patients have both the B & Rh antigens

30 patients have both the A & Rh antigens

5 patients have all 3 antigens

10 patients have none of the 3

Answer the following questions (the Venn diagram may be helpful). (1 mark each)

a) How many patients were in the study?

b) How many patients have AB+ blood?

c) What is the probability, rounded to the nearest %, of randomly selecting a person with an A + blood type?

d) What is the probability, rounded to the nearest %, of randomly selecting a person with an O - blood type?