Question

About 15​% of the population of a large country is allergic to pollenallergic to pollen. if two people are randomly​ selected, what is the probability both are allergic to pollen​? what is the probability at least one is allergic to pollenallergic to pollen​?

Answer 1

P(allergic) = 0.15

P(both are allergic to pollen) = (0.15)² = 0.0225 (you can use the binomial probability also)

Q(NOT allergic to pollen) = 1 - 0.0225 = 0.9775
Binomial probability

Probability of NEITHER is allergic
ⁿCₓ(p)ˣ(q)ⁿ⁻ˣ
²C₀(0.15)⁰(0.9775)² = 0.9555

P(at LEAST ONE is allergic) = 1- 0.9555 = 0.0444

Answer 2

Answer:

(a) 0.0225

(b) 0.225

Step-by-step explanation:

It is given that 15% of total population is allergic to pollenallergic to pollen.

Thus, Probability of an individual s/he has allergy is 0.15

Thus, The probability that two person is selected and both has allergy is 0.15 × 0.15 = 0.0225

And the Probability that at least one person is suffered from allergy from that two person = P(allergic and non-allergic) + P(non-allergic and allergic)

⇒ 0.15 × (1 - 0.15) + (1 - 0.15) × 0.15

⇒ 0.15 × 0.85 + 0.85 × 0.15 = 0.225