JEE Exam  >  JEE Questions  >  A letter is known to have come either from TA... Start Learning for Free
A letter is known to have come either from TATANAGAR or from CALCUTTA. On the envelope just two consecutive letters TA are visible. What is the probability that the letters came from TATANAGAR ?
  • a)
    7/11
  • b)
    4/11
  • c)
    24/29
  • d)
    1/11
Correct answer is option 'A'. Can you explain this answer?
Verified Answer
A letter is known to have come either from TATANAGAR or from CALCUTTA....
Ans.

Option (a)

Let E1 denote the event that the letter came from TATA NAGAR and E2 the event that the letter came from CALCUTTA.
Let A denote the event that the two consecutive alphabets visible on the envelope are TA.
Since, the letters have come either from Calcutta or Tata nagar, Therefore,
P (E1) = � and P (E2) = �
 
If E1 has occurred, then it means that the letter came from TATA NAGAR. In the word TATA NAGAR there are 8 consecutive alphabets. i.e., {TA, AT, TA, AN, NA, AG, GA and AR} and TA occurs two time.
Therefore, P (A|E1) = 2/8=1/4
 
If E2 has occurred, then it means that the letter came from Calcutta. In the word CALCUTTA there are 7 consecutive alphabets. i.e., {CA, AL, LC, CU, UT, TT and TA} and TA occurs only one time.
Therefore, P (A|E2) = 1/7
 
P (A|E1) = 2/8, P (A|E2) = 1/7. Therefore, by Bayes theorem we have,
Hence, probability that the letter has come from CALCUTTA is 4/11.
And,
Hence, probability that the letter has come from TATA NAGAR is 7/11.
View all questions of this test
Most Upvoted Answer
A letter is known to have come either from TATANAGAR or from CALCUTTA....
Given:
A letter is known to have come either from TATANAGAR or from CALCUTTA.
On the envelope just two consecutive letters TA are visible.

To find:
The probability that the letters came from TATANAGAR.

Solution:
Let's assume that the letter came from TATANAGAR (event A).
So, the probability of the letter coming from CALCUTTA (event B) is 1 - P(A) = P(B).

Let's count the number of possibilities:
- TATANAGAR has 9 letters.
- CALCUTTA has 8 letters.
- We can see two consecutive letters TA on the envelope.

For TATANAGAR, there are 2 TAs, TA_ _ _ _ _ _ _, where _ denotes any letter.
For CALCUTTA, there are 3 TAs, TA_ _ _ _ _ _ _ , _TA_ _ _ _ _ _ , and _ _TA_ _ _ _ _ , where _ denotes any letter.

The total number of possibilities is 2 + 3 = 5.

The probability of the letter coming from TATANAGAR (event A) is the number of favorable outcomes (2) divided by the total number of outcomes (5):

P(A) = 2/5

The probability of the letter coming from CALCUTTA (event B) is:

P(B) = 1 - P(A) = 3/5

Therefore, the probability that the letters came from TATANAGAR is:

P(A|TA) = P(A and TA) / P(TA)

where P(TA) is the probability of observing TA on the envelope.

The probability of observing TA on the envelope is:

P(TA) = P(A and TA) + P(B and TA)

where P(A and TA) is the probability that the letter came from TATANAGAR and TA is observed on the envelope, and P(B and TA) is the probability that the letter came from CALCUTTA and TA is observed on the envelope.

For TATANAGAR, there are 2 TAs and 7 other letters, so the probability of observing TA on the envelope is:

P(A and TA) = (2/9) * (1/8) = 1/36

For CALCUTTA, there are 3 TAs and 6 other letters for each possibility, so the probability of observing TA on the envelope is:

P(B and TA) = [(3/8) * (1/7)] + [(3/7) * (1/8)] = 9/224

Therefore, the probability of observing TA on the envelope is:

P(TA) = (1/36) + (9/224) = 47/1008

Now, we can calculate the probability that the letters came from TATANAGAR given that TA is observed on the envelope:

P(A|TA) = (2/5) * (1/36) / (47/1008) = 7/11

Therefore, the probability that the letters came from TATANAGAR given that TA is observed on the envelope is 7/11 or option (a).
Free Test
Community Answer
A letter is known to have come either from TATANAGAR or from CALCUTTA....
Ans.

Option (a)

Let E1 denote the event that the letter came from TATA NAGAR and E2 the event that the letter came from CALCUTTA.
Let A denote the event that the two consecutive alphabets visible on the envelope are TA.
Since, the letters have come either from Calcutta or Tata nagar, Therefore,
P (E1) = � and P (E2) = �
 
If E1 has occurred, then it means that the letter came from TATA NAGAR. In the word TATA NAGAR there are 8 consecutive alphabets. i.e., {TA, AT, TA, AN, NA, AG, GA and AR} and TA occurs two time.
Therefore, P (A|E1) = 2/8=1/4
 
If E2 has occurred, then it means that the letter came from Calcutta. In the word CALCUTTA there are 7 consecutive alphabets. i.e., {CA, AL, LC, CU, UT, TT and TA} and TA occurs only one time.
Therefore, P (A|E2) = 1/7
 
P (A|E1) = 2/8, P (A|E2) = 1/7. Therefore, by Bayes theorem we have,
Hence, probability that the letter has come from CALCUTTA is 4/11.
And,
Hence, probability that the letter has come from TATA NAGAR is 7/11.
Explore Courses for JEE exam
A letter is known to have come either from TATANAGAR or from CALCUTTA. On the envelope just two consecutive letters TA are visible. What is the probability that the letters came from TATANAGAR ?a)7/11b)4/11c)24/29d)1/11Correct answer is option 'A'. Can you explain this answer?
Question Description
A letter is known to have come either from TATANAGAR or from CALCUTTA. On the envelope just two consecutive letters TA are visible. What is the probability that the letters came from TATANAGAR ?a)7/11b)4/11c)24/29d)1/11Correct answer is option 'A'. Can you explain this answer? for JEE 2024 is part of JEE preparation. The Question and answers have been prepared according to the JEE exam syllabus. Information about A letter is known to have come either from TATANAGAR or from CALCUTTA. On the envelope just two consecutive letters TA are visible. What is the probability that the letters came from TATANAGAR ?a)7/11b)4/11c)24/29d)1/11Correct answer is option 'A'. Can you explain this answer? covers all topics & solutions for JEE 2024 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for A letter is known to have come either from TATANAGAR or from CALCUTTA. On the envelope just two consecutive letters TA are visible. What is the probability that the letters came from TATANAGAR ?a)7/11b)4/11c)24/29d)1/11Correct answer is option 'A'. Can you explain this answer?.
Solutions for A letter is known to have come either from TATANAGAR or from CALCUTTA. On the envelope just two consecutive letters TA are visible. What is the probability that the letters came from TATANAGAR ?a)7/11b)4/11c)24/29d)1/11Correct answer is option 'A'. Can you explain this answer? in English & in Hindi are available as part of our courses for JEE. Download more important topics, notes, lectures and mock test series for JEE Exam by signing up for free.
Here you can find the meaning of A letter is known to have come either from TATANAGAR or from CALCUTTA. On the envelope just two consecutive letters TA are visible. What is the probability that the letters came from TATANAGAR ?a)7/11b)4/11c)24/29d)1/11Correct answer is option 'A'. Can you explain this answer? defined & explained in the simplest way possible. Besides giving the explanation of A letter is known to have come either from TATANAGAR or from CALCUTTA. On the envelope just two consecutive letters TA are visible. What is the probability that the letters came from TATANAGAR ?a)7/11b)4/11c)24/29d)1/11Correct answer is option 'A'. Can you explain this answer?, a detailed solution for A letter is known to have come either from TATANAGAR or from CALCUTTA. On the envelope just two consecutive letters TA are visible. What is the probability that the letters came from TATANAGAR ?a)7/11b)4/11c)24/29d)1/11Correct answer is option 'A'. Can you explain this answer? has been provided alongside types of A letter is known to have come either from TATANAGAR or from CALCUTTA. On the envelope just two consecutive letters TA are visible. What is the probability that the letters came from TATANAGAR ?a)7/11b)4/11c)24/29d)1/11Correct answer is option 'A'. Can you explain this answer? theory, EduRev gives you an ample number of questions to practice A letter is known to have come either from TATANAGAR or from CALCUTTA. On the envelope just two consecutive letters TA are visible. What is the probability that the letters came from TATANAGAR ?a)7/11b)4/11c)24/29d)1/11Correct answer is option 'A'. Can you explain this answer? tests, examples and also practice JEE tests.
Explore Courses for JEE exam

Top Courses for JEE

Explore Courses
Signup for Free!
Signup to see your scores go up within 7 days! Learn & Practice with 1000+ FREE Notes, Videos & Tests.
10M+ students study on EduRev