Comprehension

Consider the following for the two (02) items that follow:
The probabilities that A, B and C become managers are 3/10 1/2 and 4/5 respectively. The probabilities that bonus scheme will be introduced if A, B and C become managers are 4/9, 2/9 and 1/3 respectively.

If the bonus scheme has been introduced, then what is the probability that the manager appointed was B?

This question was previously asked in
NDA-I (Mathematics) Official Paper (Held On: 13 Apr, 2025)
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  1. 5/23
  2. 6/23
  3.  7/23
  4. 8/23

Answer (Detailed Solution Below)

Option 1 : 5/23
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Detailed Solution

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Calculation:

Given,

The probability that A , B , and C  become managers are:

The conditional probabilities that the bonus scheme is introduced are:

We need to find the probability that B  is the manager given that the bonus scheme has been introduced using Bayes' Theorem:

First, calculate the total probability P(D)  that the bonus scheme is introduced:

Substitute the values:

Simplifying:

Find a common denominator (LCD = 90):

Now, use Bayes' Theorem to find P(B|D) :

Simplifying:

The probability that the manager appointed was B , given that the bonus scheme has been introduced, is 5/23.

Hence, the correct answer is Option 1.

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