Question

What is the probability of
1) a card of spade or an ace
2) neither a jack nor a king
3) either a queen or a king

Answer 1

total=52

1. spades=13
aces=4
p(AS)=13+4/52
          =17/52

2. jacks=4
kings=4
p(Njk)=52-4+4/52
          =44/52
            =11/13

3.kings=4
queens=4
p(KQ)=4+4/52
           =8/52
            =2/13

Answer 2

total no of cards in deck = 52
total no of outcomes = 52

(i) no of spades = 13
no of ace = 4
no of ace of spade = 1
no of favourable outcomes = 13 + 4 - 1 = 16
so required probability = 16/52 = 4/13



(iii) no of kings = 4
no of queens = 4
no of favourable outcomes = 4 + 4 = 8
so required probability = 8/32 = 2/13