Question 12

Mathematics Probability Easy

There are two coins, say blue and red. For blue coin, probability of getting head is 0.99 and for red coin, it is 0.01. One coin is chosen randomly and is tossed. The probability of getting head is

(A) 0.5
(B) 1
(C) 0.98
(D) 0.02
View Dynamic Solution & Explanation
Correct Solution: Option A

Step-by-step Solution:

We have two coins: - Blue coin: \(P(H|B)=0.99\). - Red coin: \(P(H|R)=0.01\). One coin is chosen at random, so \[ P(B)=P(R)=\tfrac{1}{2}. \] By the law of total probability: \[ P(H)=P(B)\cdot P(H|B)+P(R)\cdot P(H|R). \] \[ P(H)=\tfrac{1}{2}(0.99)+\tfrac{1}{2}(0.01). \] \[ P(H)=\tfrac{0.99+0.01}{2}=\tfrac{1}{2}=0.5. \] \[ \boxed{0.5} \]