JEE Exam > JEE Questions > A person throws successively with a pair of d...
Start Learning for Free
A person throws successively with a pair of dice. The chance that he throws 9 before he throws 7 is
- a)1/9
- b)2/45
- c)1/81
- d)2/5
Correct answer is option 'D'. Can you explain this answer?
| FREE This question is part of | Download PDF Attempt this Test |
Most Upvoted Answer
A person throws successively with a pair of dice. The chance that he t...
Solution:
The possible outcomes of the throw of a pair of dice are given below:
{1,1}, {1,2}, {1,3}, {1,4}, {1,5}, {1,6}, {2,1}, {2,2}, {2,3}, {2,4}, {2,5}, {2,6}, {3,1}, {3,2}, {3,3}, {3,4}, {3,5}, {3,6}, {4,1}, {4,2}, {4,3}, {4,4}, {4,5}, {4,6}, {5,1}, {5,2}, {5,3}, {5,4}, {5,5}, {5,6}, {6,1}, {6,2}, {6,3}, {6,4}, {6,5}, {6,6}
There are 6 ways to throw a 7 and 4 ways to throw a 9. Therefore, the probability of throwing a 7 before a 9 is 6/10 or 3/5.
To throw a 9 before a 7, the person must throw a 9 on the first roll, which has a probability of 4/36 or 1/9. If he does not throw a 9 on the first roll, he must throw non-7 numbers until he throws a 9 or a 7. The probability of throwing a non-7 number on any roll is 30/36 or 5/6. Therefore, the probability of throwing a 9 before a 7 is:
P(9 before 7) = P(throw 9 on first roll) + P(throw non-7 number on first roll) × P(throw 9 before 7 on subsequent rolls)
P(9 before 7) = 1/9 + 5/6 × P(9 before 7)
Solving for P(9 before 7), we get:
P(9 before 7) = 2/5
Therefore, the chance that he throws 9 before he throws 7 is 2/5.
The possible outcomes of the throw of a pair of dice are given below:
{1,1}, {1,2}, {1,3}, {1,4}, {1,5}, {1,6}, {2,1}, {2,2}, {2,3}, {2,4}, {2,5}, {2,6}, {3,1}, {3,2}, {3,3}, {3,4}, {3,5}, {3,6}, {4,1}, {4,2}, {4,3}, {4,4}, {4,5}, {4,6}, {5,1}, {5,2}, {5,3}, {5,4}, {5,5}, {5,6}, {6,1}, {6,2}, {6,3}, {6,4}, {6,5}, {6,6}
There are 6 ways to throw a 7 and 4 ways to throw a 9. Therefore, the probability of throwing a 7 before a 9 is 6/10 or 3/5.
To throw a 9 before a 7, the person must throw a 9 on the first roll, which has a probability of 4/36 or 1/9. If he does not throw a 9 on the first roll, he must throw non-7 numbers until he throws a 9 or a 7. The probability of throwing a non-7 number on any roll is 30/36 or 5/6. Therefore, the probability of throwing a 9 before a 7 is:
P(9 before 7) = P(throw 9 on first roll) + P(throw non-7 number on first roll) × P(throw 9 before 7 on subsequent rolls)
P(9 before 7) = 1/9 + 5/6 × P(9 before 7)
Solving for P(9 before 7), we get:
P(9 before 7) = 2/5
Therefore, the chance that he throws 9 before he throws 7 is 2/5.
Attention JEE Students!
To make sure you are not studying endlessly, EduRev has designed JEE study material, with Structured Courses, Videos, & Test Series. Plus get personalized analysis, doubt solving and improvement plans to achieve a great score in JEE.
|
Explore Courses for JEE exam
|
|
Similar JEE Doubts
Top Courses for JEEView all
A person throws successively with a pair of dice. The chance that he throws 9 before he throws 7 isa)1/9b)2/45c)1/81d)2/5Correct answer is option 'D'. Can you explain this answer?
Question Description
A person throws successively with a pair of dice. The chance that he throws 9 before he throws 7 isa)1/9b)2/45c)1/81d)2/5Correct answer is option 'D'. 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 person throws successively with a pair of dice. The chance that he throws 9 before he throws 7 isa)1/9b)2/45c)1/81d)2/5Correct answer is option 'D'. 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 person throws successively with a pair of dice. The chance that he throws 9 before he throws 7 isa)1/9b)2/45c)1/81d)2/5Correct answer is option 'D'. Can you explain this answer?.
A person throws successively with a pair of dice. The chance that he throws 9 before he throws 7 isa)1/9b)2/45c)1/81d)2/5Correct answer is option 'D'. 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 person throws successively with a pair of dice. The chance that he throws 9 before he throws 7 isa)1/9b)2/45c)1/81d)2/5Correct answer is option 'D'. 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 person throws successively with a pair of dice. The chance that he throws 9 before he throws 7 isa)1/9b)2/45c)1/81d)2/5Correct answer is option 'D'. Can you explain this answer?.
Solutions for A person throws successively with a pair of dice. The chance that he throws 9 before he throws 7 isa)1/9b)2/45c)1/81d)2/5Correct answer is option 'D'. 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 person throws successively with a pair of dice. The chance that he throws 9 before he throws 7 isa)1/9b)2/45c)1/81d)2/5Correct answer is option 'D'. Can you explain this answer? defined & explained in the simplest way possible. Besides giving the explanation of
A person throws successively with a pair of dice. The chance that he throws 9 before he throws 7 isa)1/9b)2/45c)1/81d)2/5Correct answer is option 'D'. Can you explain this answer?, a detailed solution for A person throws successively with a pair of dice. The chance that he throws 9 before he throws 7 isa)1/9b)2/45c)1/81d)2/5Correct answer is option 'D'. Can you explain this answer? has been provided alongside types of A person throws successively with a pair of dice. The chance that he throws 9 before he throws 7 isa)1/9b)2/45c)1/81d)2/5Correct answer is option 'D'. Can you explain this answer? theory, EduRev gives you an
ample number of questions to practice A person throws successively with a pair of dice. The chance that he throws 9 before he throws 7 isa)1/9b)2/45c)1/81d)2/5Correct answer is option 'D'. Can you explain this answer? tests, examples and also practice JEE tests.
|
|
Explore Courses for JEE exam
|
|
Suggested Free Tests
Signup for Free!
Signup to see your scores go up within 7 days! Learn & Practice with 1000+ FREE Notes, Videos & Tests.
|
© EduRev
|
Education Revolution
|
Follow Us
|
Signup to see your scores
go up
within 7 days!
within 7 days!
Takes less than 10 seconds to signup