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  1. A brother and sister appear for an interview against two vacant posts in an office. The probability of the brother's selection is 1/5th and that of the sister's selections is 1/3rd. What is the probability that one of them is selected ?
    1. 1/5
    2. 2/5
    3. 1/3
    4. 2/3
Correct Option: B

One of them can be selected in the following ways.
Brother is selected and sister is not selected.
or
Brother is not selected and sister is selected.

∴ Required probability = 1/5 x 2/3 + 4/5 x 1/3
= 2/15 + 4/15 = 6/15 = 2/5



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