Mbelo cannot remember the correct order of the seven letters in her password (which is not case sensitive). She does recall that she used the first seven letters of the alphabet.
1. What is the probability that the first 3 letters of her password are consonants?
2. What is the probability that the first 2 letters of her password are vowels?
Statistics Probability Question?
2016-02-26 4:25 pm
回答 (3)
2016-02-26 4:51 pm
✔ 最佳答案
1.Out of the 26 letters, 5 (a, e, i, o, u) are vowels, and the rest 21 are consnants.
P(a vowel letter) = 5/26
P(a consonant letter) = 21/26
P(first 3 letters are consonants)
= P(1st letter is consonant) × P(2nd letter is consonant) × P(3nd letter is consonant)
= (21/26)³
= 9261/17576
2.
P(first 2 letters are vowels)
= P(1st letter is vowel) × (2nd letter is vowel)
= (5/26)²
= 25/676
2016-02-26 4:29 pm
1. there are a total of 7*7*7 or 343 total possible combinations of letters in 1st 3 blanks. So consonants are B,C,D,F,G so there are 125 combos with consonants. therefore probability is 125/343
2. same thing here: 49 combos 1st 2 letters. 2 vowels so 4 possible combos: 4/49
2. same thing here: 49 combos 1st 2 letters. 2 vowels so 4 possible combos: 4/49
2016-02-26 4:25 pm
not my field
收錄日期: 2021-04-18 14:39:47
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20160226082517AAK7IQs