Question

Mrs. R is pregnant and very worried that the child will have beta-thalassemia. What is the probability that the child will have beta-thalassemia major? What is the probability that the child will have no trace of the disease?

Answer 1

There are three kind of beta-thalassemia.

Total possible outcome= 3 types of beta- thalassemia + 1 [child will have no trace of disease] = 4

As we know Probability(outcome) =
`\frac{\text{ Total favorable outcome}}\text{Total possible outcome}`

Probability that the child will have beta-thalassemia major =\frac{_{1}^{3}\textrm{C}}{_{1}^{4}\textrm{C}}

=
`(3)/(4)`

∴ favorable=
`_(1)^(3)\textrm{C}`

And , Total =
`_(1)^(4)\textrm{C}`

Probability that the child will have no trace of the disease=
`(1)/(4)`