Aptitude Discussion

Q. |
In a game there are 70 people in which 40 are boys and 30 are girls, out of which 10 people are selected at random. One from the total group, thus selected is selected as a leader at random. What is the probability that the person, chosen as the leader is a boy? |

✔ A. |
4/7 |

✖ B. |
4/9 |

✖ C. |
5/7 |

✖ D. |
2/7 |

**Solution:**

Option(**A**) is correct

The total groups contains boys and girls in the ratio $4:3$

If some person are selected at random from the group, the expected value of the ratio of boys and girls will be $4:3$

If the leader is chosen at random from the selection, the probability of him being a boy = **4/7**

**Mayukh Mitra**

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I believe you have a messed up notion about the 'ratio'. It is like percentage. You do not necessarily deal with the actual numbers, you try to analyse the scenario.

**Giree**

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Could not accept that presumed 4:3 for 10 persons selected

if 4:3 is taken as the same ratio in a group of 10 people then it would give sum of 7 people which is less than 10. also if you assume x as no.of boys and x-10 as no.of girls then that would result in total of 35 people since x would be equal to 5. so if we walk with 4:3 then total gives 7. therefore 3 people must either boys or girls. so the ratio would become 4:6 or 7:3 so that equation satisfies.