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04 Dec 2022, 14:03
Kudos
Bookmarks
D
Be sure to select an answer first to save it in the Error Log before revealing the correct answer (OA)!
Difficulty:
85%
(hard)
Question Stats:
60% (02:58) correct
40%
(02:34)
wrong
based on 195
sessions
History
Date
Time
Result
Not Attempted Yet
A bookshelf has an equal number of books in the following genres: history, biography, novel and anthology. One-half of each genre on the bookshelf is red, one-third of each genre on the bookshelf is blue, and one-sixth of each genre on the bookshelf is brown. If a book is randomly chosen from the shelf, what is the difference between the probability that the book is not a red history book and the probability that it is a blue or brown novel?
(A) -3/4
(B) 0
(C) 1/8
(D) 3/4
(E) 7/8
(A) -3/4
(B) 0
(C) 1/8
(D) 3/4
(E) 7/8
05 Dec 2022, 01:55
Kudos
Bookmarks
Bunuel
Solution:
- Based on the given data, let the number of books of each genre be 60
- Then we can form the following table:
Attachment:
genre.png [ 16.06 KiB | Viewed 3153 times ]
- Probability of picking red history book \(=\frac{30}{240}=\frac{1}{8}\)
- Probability of not red history book \(=1-\frac{1}{8}=\frac{7}{8}\)
- Probabiity of blue or brown novel \(=\frac{20+10}{240}=\frac{30}{240}=\frac{1}{8}\)
- Rewired difference \(=\frac{7}{8}-\frac{1}{8}=\frac{6}{8}=\frac{3}{4}\)
Hence the right answer is Option D
11 Mar 2024, 00:01
Kudos
Bookmarks
Bunuel
Hello Bunuel, I thought the probability of the book is either Blue or Brown supposed to be 1/2?
Does this question really mean the Blue or Brown History book only?
