जॉइन Examsbookउत्तर : 4. "1/14"
The first 8 alphabets are written down at random. what is the probability that the letters b,c,d,e always come together ?5
प्र: The first 8 alphabets are written down at random. what is the probability that the letters b,c,d,e always come together ?
- 11/7false
- 28!false
- 37!false
- 41/14true
- उत्तर देखें
- Workspace
उत्तर : 4. "1/14"
व्याख्या :
Answer: D) 1/14 Explanation: The 8 letters can be written in 8! ways.n(S) = 8!Let E be the event that the letters b,c,d,e always come together when the first 8 alphabets are written down.Now the letters a, (bcde), f, g and h can be arranged in 5! ways.The letters b,c,d and e can be arranged themselves in 4! ways.n(E) = 5! x 4!Now, the required P(E) = n(E)/n(S) = 5! x 4!/8! = 1/14Hence the answer is 1/14.