There are three types of blood antigens that determine blood type: A, B, and Rh+. An individual's blood type is determined by the specific combination of these antigens. In order to receive a blood transfusion, you can't receive blood from a donor who has an antigen that you don't have yourself. That means that people with AB+ blood can receive a transfusion from ANY donor, since they have all of the possible antigens. They can only donate to other people with AB+. People with O- blood (none of the antigens) can only receive type O- blood, since all other blood types have at least one of the antigens. However, they can donate their blood to anyone, since their blood does not have any of the antigens. A laboratory looked at blood samples for 200 patients and found the following information provided in the table. How many patients were classified as O-?
Number of samples
Antigen in blood
80
A
36
B
82
Rh
10
A and B
62
A and Rh
22
B and Rh
4
A, B, and Rh