Target Exam

CUET

Subject

-- Applied Mathematics - Section B2

Chapter

Probability Distributions

Question:

A coin is biased so that the head is 3 times likely to occur as tail. If the coin is tossed twice, then the probability distribution of number of tails is :

Options:
x 0 1 2
P(x) 9/16 6/16 1/16

 

x 0 1 2
P(x) 9/16 1/16 6/16

 

x 0 1 2
P(x) 1/16 6/16 9/16
x 0 1 2
P(x) 1/16 9/16 6/16



Correct Answer:
x 0 1 2
P(x) 9/16 6/16 1/16

 

Explanation:

The correct answer is Option (1) → 

x 0 1 2
P(x) 9/16 6/16 1/16

$P(Head)=3P(Tail)$

$⇒P(Head)+P(Tail)=1$

$⇒3P(Tail)+P(Tail)=1$

$⇒P(Tail)=\frac{1}{4}$

$P(Tail=0)=\frac{3}{4}×\frac{3}{4}=\frac{9}{16}$

$P(Tail=1)=\frac{3}{4}×\frac{1}{4}×2=\frac{6}{16}$

$P(Tail=2)=\frac{1}{4}×\frac{1}{4}=\frac{1}{16}$