NCERT Exemplar Solutions
Class 10 - Mathematics - CHAPTER 13: Statistics and Probability - Exercise 13.3
Question 41

Question. 41

A bag has 24 balls: \(x\) red, \(2x\) white, \(3x\) blue. One ball drawn. Find probability it is (i) not red (ii) white.

Answer:

(i) \(\dfrac{5}{6}\), (ii) \(\dfrac{1}{3}\)

Detailed Answer with Explanation:

Step 1: Write total balls in terms of \(x\).

Total = red + white + blue = \(x + 2x + 3x = 6x\).

We are told total = 24, so:

\(6x = 24\)

\(x = 4\)

Step 2: Find actual numbers of each colour.

  • Red balls = \(x = 4\)
  • White balls = \(2x = 8\)
  • Blue balls = \(3x = 12\)

Total check: \(4 + 8 + 12 = 24\) ✔

Step 3: Recall probability formula.

Probability = \(\dfrac{\text{Favourable outcomes}}{\text{Total outcomes}}\)

Total outcomes = 24 (since there are 24 balls).

Step 4: (i) Probability of not red.

‘Not red’ means either white or blue.

Number of not red balls = white + blue = \(8 + 12 = 20\).

So, probability = \(\dfrac{20}{24} = \dfrac{5}{6}\).

Step 5: (ii) Probability of white.

Number of white balls = 8.

So, probability = \(\dfrac{8}{24} = \dfrac{1}{3}\).

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