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A bag contains 4 red, 5 blue and 3 green balls. If two balls are drawn at random from the bag, then which of the following statements are correct?

(A) The probability that both balls are red is 1/11.

(B) The probability that one ball is red, and one ball is blue is 10/33

(C) The probability that both balls are blue is 5/33.

(D) The probability that both balls are green is 5/11.

Choose the correct answer from the options given below:

Solution

✅ Correct Option: 1

Red balls = 4

Blue balls = 5

Green balls = 3

Total balls = 12


When drawing 2 balls from 12 balls, the total number of ways is:

Total ways = C(12,2)C(12,2)

=12×112×1= \dfrac{12 \times 11}{2 \times 1}

=1322= \dfrac{132}{2}

=66= 66


Statement (A): Both balls are red = 111\dfrac{1}{11}

Ways to choose 2 red from 4 red balls:

C(4,2)C(4,2)

=4×32×1= \dfrac{4 \times 3}{2 \times 1}

=6= 6

Probability =666=111= \dfrac{6}{66} = \dfrac{1}{11}

Statement (A) is correct.


Statement (B): One red and one blue = 1033\dfrac{10}{33}

Ways to choose 1 red from 4 = 4

Ways to choose 1 blue from 5 = 5

Total ways = 4×5=204 \times 5 = 20

Probability =2066=1033= \dfrac{20}{66} = \dfrac{10}{33}

Statement (B) is correct.


Statement (C): Both balls are blue = 533\dfrac{5}{33}

Ways to choose 2 blue from 5 blue balls:

C(5,2)C(5,2)

=5×42×1= \dfrac{5 \times 4}{2 \times 1}

=10= 10

Probability =1066=533= \dfrac{10}{66} = \dfrac{5}{33}

Statement (C) is correct.


Statement (D): Both balls are green = 511\dfrac{5}{11}

Ways to choose 2 green from 3 green balls:

C(3,2)C(3,2)

=3×22×1= \dfrac{3 \times 2}{2 \times 1}

=3= 3

Probability =366=122= \dfrac{3}{66} = \dfrac{1}{22}

This is not equal to 511\dfrac{5}{11}.

Statement (D) is incorrect.


Statements (A), (B) and (C) are correct.

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