4 main blood types are A, B, AB, and O. The letters A and B ndicate whether 2 factors (particular molecules...

Question

on the surface of the blood cells) are present. Thus, type AB blood has both factors while type O has neither. Roughly 42% of the population have type A blood, 10% have type B, 32% have type AB, and 45% have type O. What is the probability that a person.

a) has blood factor A?

b) does not have blood factor B?

Answer 1

a) 0.42 + 0.32 = 0.74 --> 74%

(Add the probabilities of type A and type AB)

b) 1 - 0.10 - 0.32 = 0.58 --> 58%

(Subtract out both the possibility of type B and type AB to get 58%)

Answer 2

The chance that someone has blood factor A is is the chance that someone has either blood type A or blood type AB. According to your data, the chance for blood type A is 45%, the chance for blood type AB is  32% add these up and you get:

Chance where X is the factor in the blood

P(X=A) = 0.42 + 0.32 = 0.74 --> thus a 74% chance.

The chance that someone does not have blood factor B is

equal to the chance of blood type AB (42%) and blood type B(10%), thus

Chance where X is the factor in the blood

P(X=B) = 0.32 + 0.10 = 0.42 --> thus a 42% chance.

So the chance that someone does NOT have factor B in their blood is

1 - P(X = B) = 1 - 0.42 = 0.58 --> thus 58% chance that someone does NOT have factor B in their blood.

Hope this helped