Question

Two coins are tossed. Then the probability distribution of number of tails is.

Options

• X	1	2	3
  P(X)	`1/4`	`1/2`	`1/4`

• X	0	1	2
  P(X)	`1/4`	`1/2`	`1/4`

• X	0	1	2
  P(X)	`1/4`	`1/4`	`1/2`

• X	1	2	3
  P(X)	`1/4`	`1/4`	`1/2`

Answer 1

X	0	1	2
P(X)	`1/4`	`1/2`	`1/4`

Explanation:

Let X denotes the number of tails.

Thus, the possible values ofX are 0, 1 and 2

P(X = 0) = P(getting no tail)

= P(HH) = `1/4`

P(X = 1) = P(getting one tail)

= P(TH, HT) = `1/2`

P(X = 2) = P(getting two tails)

= P(TT) = `1/4`