Q) A coin is tossed 2 times. What is the probability of getting at least one Head ? প্ৰশ্নঃ এটা মুদ্ৰা ২ বাৰ উছৰিলে অন্ততঃ এটা Head পোৱাৰ সম্ভাৱনা কিমান ?

Options / বিকল্পঃ (a) 25%  (b) 50%  (c) 75%  (d) 100%

Solution / সমাধান:

Possible outcomes / সম্ভৱ ফলাফল: HH, HT, TH, TT = 4

At least one Head / অন্ততঃ এটা Head থকা ফলাফল: HH, HT, TH = 3

P(Head) = 3​/4 = 3/4 ​× 100 = 75%​

Ans / উত্তৰ: (c) 75%

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Q. A card is drawn from a pack of 52 playing cards. What is the probability of getting a Queen ?

(A) 1/4  (B) 1/13  (C) 1/52  (D) 1/26

Solution:

Total number of cards = 52

There are 4 Queens in a standard deck:

• ♠ Queen of Spades


• ♥ Queen of Hearts


• ♦ Queen of Diamonds


• ♣ Queen of Clubs

Favourable outcomes = 4

P(Queen) = Favourable outcomes​/Total outcomes = 4/52​ = 1/13

Ans: (B) 1/13

Trick: 52 cards → 4 Queens → 4/52 = 1/13

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Q. A card is drawn from a pack of 52 playing cards. What is the probability of getting a Red King ?

(A) 1/4  (B) 1/13  (C) 1/2  (D) 1/26

Solution

A standard deck has 52 cards.

There are 2 Red Kings:

• ♥ King of Hearts


• ♦ King of Diamonds

​Formula : P(E) = Favourable Outcomes​​ / Total Outcomes

P(Red King) = 2​/52 = 1​​/26

Ans: (D) 1/26

Trick: Total cards = 52, Red Kings = 2

2/52​ = 1/26​