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MathsCBSE Class 10 · Basic · Board exam 2026, set 430/3/1 · 3 marks · Short answer

CBSE Class 10 Mathematics Basic 2026: question 30

Set in the CBSE Class 10 board exam of 2026, paper 430/3/1, section C, question 30, for 3 marks. Try it first; the hints and our step-by-step solution are below.

Q30 · 3 marks · Short answerProbability

A box contains 6 blue, 4 white and 8 red marbles. A marble is drawn at random from this box. Find the probability that the marble so drawn is:

  1. (i)

    white

    1 mark
  2. (ii)

    white or red

    1 mark
  3. (iii)

    not red

    1 mark

Source: official question paper from cbse.gov.in (PDF). See it in the full 2026 board paper, set 430/3/1.

Hints

Open one hint at a time and try again before the next.

Hint 1

First find the total number of marbles.

Hint 2

Count the favourable marbles for each event.

Hint 3

For 'not red', count the blue and white marbles, or use .

Step-by-step solution

Each step shows the marks it earns, as an examiner would award them. Checked by an independent re-solve from the question paper.

  1. Total number of marbles , so there are 18 equally likely outcomes.

  2. (i) P(white)

    1 mark
  3. (ii) Marbles that are white or red , so P(white or red)

    1 mark
  4. (iii) Marbles that are not red , so P(not red)

    1 mark

Answer: (i) ; (ii) ; (iii)

Where the marks are

  • P(white) = 2/9 (1 mark)
  • P(white or red) = 2/3 (1 mark)
  • P(not red) = 5/9 (1 mark)

Revise the chapter

The question is transcribed from the official paper; figures are described in words. The solution, hints and chapter tag are ours. Spotted an error? Write tosupport@questionbuddy.in.