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A bag contains 3 red, 4 white and 7 black balls. The probability of drawing a red or a black ball, is

4/7
1/7
5/7
3/7

Correct Answer: 5/7

Explanation:

Here, total balls are 14.
∴ Required probability = (³c₁ + ⁷c₁) / ¹⁴c₁
= (3 + 7)/14
= 10/14
= 5/7

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