A card from a 52 card deck is lost. We then draw 2 cards from the 51 remaining cards. What is the probability they are both diamonds?

Respuesta :

Answer:

[tex]\frac{1}{17}[/tex]

Explanation:

Let D be the event that the lost card is a diamond

and D' be the event that the lost card is a non diamond

Therefore,

P(D) = [tex]\frac{13}{52}[/tex] = 0.25

P(D') = [tex]\frac{39}{52}[/tex] = 0.75

Now,

Event that the cards picked up are both diamonds = A

Thus,

P( A | D) = [tex]\frac{12}{51 }\times\frac{11}{50}[/tex]               [ As One Diamond Card is lost ]

And,

P(A | D') = [tex]\frac{13}{51}\times\frac{12}{50}[/tex]                [ As One Non-Diamond card is lost ]

Therefore,

P(A) = P(D) × P(A | D) + P(D') × P( A | D')  

= 0.25 × [tex]\frac{12}{51 }\times\frac{11}{50}[/tex]  + 0.75 ×  [tex]\frac{13}{51}\times\frac{12}{50}[/tex]

= [tex]\frac{1}{17}[/tex]