# A coin is biased so that the head is three times as likely to occur as tail. If the coin is tossed twice, find the probability distribution of number of tails. Hence find the mean of the number of tails.

$P(H) = \frac{3}{4}$

$P(T) = \frac{1}{4}$

X : Number of tails

X: 0,1,2

 X P(X) X.P(X) 0 $\frac{3}{ 4} \times \frac{3}{4}$ 0 1 $2 \times \frac{1}{ 4} \times \frac{3}{4}$ $\frac{6}{16}$ 2 $\frac{1}{ 4} \times \frac{1}{4}$ $\frac{2}{16}$

$\\ \text { Mean }=\sum X \cdot P(X) \\\\ =0+ \frac{6}{16}+ \frac{2}{16} \\\\= \frac{1}{2}$

## Related Chapters

### Preparation Products

##### Knockout JEE Main April 2021 (One Month)

Personalized AI Tutor and Adaptive Time Table, Self Study Material, Weekend Live Classes, Mentorship from our Experts, Unlimited Mock Tests and Personalized Analysis Reports, 24x7 Doubt Chat Support,.

₹ 14000/- ₹ 4999/-
##### Knockout NEET Aug 2021 (One Month)

Personalized AI Tutor and Adaptive Time Table, Self Study Material, Weekend Live Classes, Mentorship from our Experts, Unlimited Mock Tests and Personalized Analysis Reports, 24x7 Doubt Chat Support,.

₹ 14000/- ₹ 4999/-
##### Knockout JEE Main May 2021

Personalized AI Tutor and Adaptive Time Table, Self Study Material, Weekend Live Classes, Mentorship from our Experts, Unlimited Mock Tests and Personalized Analysis Reports, 24x7 Doubt Chat Support,.

₹ 22999/- ₹ 9999/-
##### Knockout NEET Aug 2021

Personalized AI Tutor and Adaptive Time Table, Self Study Material, Weekend Live Classes, Mentorship from our Experts, Unlimited Mock Tests and Personalized Analysis Reports, 24x7 Doubt Chat Support,.

₹ 22999/- ₹ 9999/-