Home
Class 8
MATHS
Aman A speaks truth in 80% of the cases ...

Aman A speaks truth in 80% of the cases and another man B in 90% of the cases. While stating the same fact, what is the probability that they contradict?

A

`(37)/(50)`

B

`(13)/(50)`

C

`(16)/(50)`

D

None of these

Text Solution

AI Generated Solution

The correct Answer is:
To find the probability that Aman A and man B contradict each other while stating the same fact, we can break down the problem into steps. ### Step-by-Step Solution: 1. **Identify the probabilities of speaking the truth:** - Probability that A speaks the truth (P(A)) = 80% = 0.8 - Probability that B speaks the truth (P(B)) = 90% = 0.9 2. **Calculate the probabilities of lying:** - Probability that A lies (P(A')) = 1 - P(A) = 1 - 0.8 = 0.2 - Probability that B lies (P(B')) = 1 - P(B) = 1 - 0.9 = 0.1 3. **Determine the scenarios for contradiction:** - Scenario 1: A speaks the truth and B lies. - Scenario 2: A lies and B speaks the truth. 4. **Calculate the probability for each scenario:** - **Scenario 1:** Probability that A speaks the truth and B lies: \[ P(A \text{ and } B') = P(A) \times P(B') = 0.8 \times 0.1 = 0.08 \] - **Scenario 2:** Probability that A lies and B speaks the truth: \[ P(A' \text{ and } B) = P(A') \times P(B) = 0.2 \times 0.9 = 0.18 \] 5. **Add the probabilities of the two scenarios to find the total probability of contradiction:** \[ P(\text{Contradiction}) = P(A \text{ and } B') + P(A' \text{ and } B) = 0.08 + 0.18 = 0.26 \] 6. **Convert the probability into a fraction:** - 0.26 can be expressed as \( \frac{26}{100} \), which simplifies to \( \frac{13}{50} \). ### Final Answer: The probability that Aman A and man B contradict each other is \( \frac{13}{50} \). ---
Promotional Banner

Topper's Solved these Questions

  • PROBABILITY

    S CHAND IIT JEE FOUNDATION|Exercise Self Assessment Sheet |10 Videos
  • PROBABILITY

    S CHAND IIT JEE FOUNDATION|Exercise QUESTION BANK -30|20 Videos
  • PROBABILITY

    S CHAND IIT JEE FOUNDATION|Exercise Solved Examples |8 Videos
  • POLYGONS AND QUADRILATERALS

    S CHAND IIT JEE FOUNDATION|Exercise SELF ASSESSMENT SHEET - 23 |10 Videos
  • QUADRATIC EQUATIONS

    S CHAND IIT JEE FOUNDATION|Exercise SELF ASSESSMENT SHEET|10 Videos
S CHAND IIT JEE FOUNDATION-PROBABILITY-Question Bank
  1. In a test, the marks obtained by 15 students are 34, 37, 44, 39, 45, 4...

    Text Solution

    |

  2. Which of the following pairs of events is not mutually exclusive?

    Text Solution

    |

  3. An electronic machine choses random numbers from 1 to 30. What is the ...

    Text Solution

    |

  4. In a simultaneous toss of two coins, find the probability of getting t...

    Text Solution

    |

  5. Three coins are tossed simultaneously. Find the probability of at leas...

    Text Solution

    |

  6. In a single throw of two dice, what is the probability of getting a to...

    Text Solution

    |

  7. A bag contains 4 blue, 5 red and 7 green balls. If 4 balls are drawn o...

    Text Solution

    |

  8. The set S’ = {n : n is an integer, 1 le n le 50}. If an element of S i...

    Text Solution

    |

  9. In a single throw of two dice, find the probability of getting a doubl...

    Text Solution

    |

  10. What is the probability that a card drawn at random from a pack of pla...

    Text Solution

    |

  11. Two dice are thrown. Find the odds in favour of getting the sum 4.

    Text Solution

    |

  12. A machine generates a two-digit number randomly. Find the probability ...

    Text Solution

    |

  13. From a pack of cards, two are drawn, the first being replaced before t...

    Text Solution

    |

  14. If A and B are two mutually exclusive and exhaustive events with P(B) ...

    Text Solution

    |

  15. The probability that a student passes in mathematics is 4/9 and that h...

    Text Solution

    |

  16. An aircraft has three engines A, B and C. The aircraft crashes if all ...

    Text Solution

    |

  17. A card is drawn from an ordinary pack of 52 cards and a gambler bets ...

    Text Solution

    |

  18. A problem in statistics is given to four students A,  B, C and D. Thei...

    Text Solution

    |

  19. Aman A speaks truth in 80% of the cases and another man B in 90% of th...

    Text Solution

    |

  20. From a bag containing 60 standard and 40 substandard articles, two art...

    Text Solution

    |