A bag contains 3 maths books, 3 english books and 4 science books. One book is taken out from the bag. Find the probability what the book drawn is a (options 1- Maths book, 2- English book, 3- Science book)
Answers
Answer:
In how many ways 4 books of maths and 3 books of physics are placed on shelf that same subject books are always together?
In how many ways can 4 books of maths and 3 books of physics be placed on a shelf so all books of the same subject books are together?
Since the subjects must be together, there must be all of the math books must be on one end of the shelf and all of the physics book on the other end. Therefore, there are only two arrangements of the subjects: 4 math followed by 3 physics OR 3 physics followed by 4 math.
Within each subject, the number of permutations is
4! = 4*3*2*1 = 24 for the physics books
3! = 3*2*1 = 6 for the physics books
Thus, the number of possible ways to place the books is: 2 * 24 * 6 = 288
Answer:
1. Total number of Maths book =3
Total number of books = 10
Probability=Total number of Maths book/Total number of books
= 3/10
2. Total number of English books = 3
Total number of books = 10
Probability = 3/10
3. Total number of Science books = 4
Total number of books = 10
Probability = 4/10 = 2/5