Aptitude Discussion

Q. |
A bag contains 3 white balls and 2 black balls. Another bag contains 2 white and 4 black balls. A bag and a ball are picked random. The probability that the ball will be white is: |

✖ A. |
7/11 |

✖ B. |
7/30 |

✖ C. |
5/11 |

✔ D. |
7/15 |

**Solution:**

Option(**D**) is correct

The probability of selecting one bag \(=\dfrac{1}{2}\)

Now, probability of getting a white ball from bag $A$:

\(=\dfrac{1}{2}\times \dfrac{3}{5}=\dfrac{3}{10}\)

and probability of getting a white ball from bag $B$:

\(=\dfrac{1}{2}\times \dfrac{2}{6}=\dfrac{1}{6}\)

Hence, Probability that white ball is drawn either first or second bag:

$= 3/10 + 1/6 = 7/15$

**Raj**

*()
*

It sure is related since it has to be picked from one of the two available bags. White ball coming from bag 1 has different probability than white ball coming from bag 2.

In other words, the probability is different when same balls are kept inside one bag only.

The probability of picking a ball should not have any relation with picking the bag