Mr. Gordon’s science class is studying blood types. The table below shows the probability that a person living in the US has a particular blood type.

the probability of having a blood type: O= 9/20; A= 41/100; B= 1/10; and AB= 1/25
What is the probability that three students selected randomly from the class will have A, B, and AB blood, respectively?

1 answer

To find the probability that three randomly selected students will have blood types A, B, and AB respectively, we multiply the individual probabilities of each blood type.

Given the probabilities:

  • Probability of blood type A: \( P(A) = \frac{41}{100} \)
  • Probability of blood type B: \( P(B) = \frac{1}{10} = \frac{10}{100} \)
  • Probability of blood type AB: \( P(AB) = \frac{1}{25} = \frac{4}{100} \)

Now we will calculate the combined probability:

\[ P(A, B, AB) = P(A) \times P(B) \times P(AB) \]

Substituting the values:

\[ P(A, B, AB) = \left(\frac{41}{100}\right) \times \left(\frac{10}{100}\right) \times \left(\frac{4}{100}\right) \]

Now, let's do the multiplication step-by-step:

\[ = \frac{41 \times 10 \times 4}{100 \times 100 \times 100} \] \[ = \frac{1640}{1000000} \]

Now we can simplify this fraction:

\[ = \frac{164}{100000} \]

Thus, the probability that three randomly selected students will have blood types A, B, and AB respectively is:

\[ \frac{164}{100000} \]

Or, as a decimal:

\[ 0.00164 \]

Therefore, the probability is \( \frac{164}{100000} \) or \( 0.00164 \).