Question

Determine P(E|F).

Two coins are tossed once, where 

E: tail appears on one coin, F: one coin shows head

Answer 1

S = {HH, TH, HT, TT}

n(S) = 4

E : A coin shows tails,

E = {TH, HT}

P(E) = `1/2`

F: Head appears on a coin,

F = {TH, HT}

P(F) = `1/2`

E ∩ F = {TH, HT}

n(E ∩ F) = 2

P(E ∩ F) = `2/4 = 1/2`

Thus, P(E | F) = `(P(E ∩ F))/(P(F))`

`= (1/2)/(1/2)`

= 1