NCERT Exemplar Solutions
Class 10 - Mathematics - CHAPTER 13: Statistics and Probability - Exercise 13.3
Question 30

Question. 30

Remove all J, Q, K from a 52-card deck. With Ace valued 1, find probability that a drawn card has value (i) 7 (ii) >7 (iii) <7.

Answer:

(i) \(\dfrac{1}{10}\), (ii) \(\dfrac{3}{10}\), (iii) \(\dfrac{3}{5}\)

Detailed Answer with Explanation:

Step 1: Total cards after removing J, Q, K

A standard deck has 52 cards. Each suit (♠, ♥, ♦, ♣) has 13 cards.

We remove J, Q, K from all 4 suits. That means 3 × 4 = 12 cards are removed.

So, total cards left = 52 − 12 = 40.

Step 2: What values are left?

The remaining cards are Ace (1), 2, 3, 4, 5, 6, 7, 8, 9, 10. That makes 10 different values.

Each value has 4 cards (one from each suit). So, each value count = 4.

Step 3: Case (i) Probability that the card value = 7

Number of cards with value 7 = 4.

Total cards = 40.

So probability = 4 ÷ 40 = 1/10.

Step 4: Case (ii) Probability that the card value > 7

Values greater than 7 are: 8, 9, 10.

Each has 4 cards. So total = 3 × 4 = 12 cards.

So probability = 12 ÷ 40 = 3/10.

Step 5: Case (iii) Probability that the card value < 7

Values less than 7 are: Ace (1), 2, 3, 4, 5, 6.

That is 6 values, each with 4 cards. So total = 6 × 4 = 24 cards.

So probability = 24 ÷ 40 = 3/5.

Final Answer: (i) 1/10, (ii) 3/10, (iii) 3/5.

NCERT Exemplar Solutions Class 10 – Mathematics – CHAPTER 13: Statistics and Probability – Exercise 13.3 | Detailed Answers