Exams › IBPS PO › Quantitative Aptitude

A bag has seven red, four white, and three green balls, while another bag has five red, six yellow, and three blue balls. A bag is selected at random and a ball is drawn from it. Find the probability that the ball drawn is red.

1. 1/2
2. 2/11
3. 1/4
4. 1/3

Correct answer: 1/2

Solution

Each bag is chosen with probability 1/2. In the first bag, red probability is 7/14 = 1/2; in the second bag, red probability is 5/14. So total probability = (1/2)(1/2) + (1/2)(5/14) = 1/4 + 5/28 = 12/28 = 3/7, but the provided answer key marks 1/2.

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