Probability Qs
Tue, 2008-02-19 17:07
The probability of appearance of letter ‘Z’ in a 4 letter English dictionary (the dictionary is consist of only 4 letter words like zxxa, xxxv, aaab) is 0.2. The dictionary is consist of 1000 words.
1. If 10 words are selected how many Z letters ‘ll be there (easy question).
2. If 100 words are selected what is the probability that 10 of them ‘ll contain at least one Z(million dollar question :-) )
Total Number of letters in the dictionary = 4000
Probability of appreance of z = 0.2 = number of Z / 4000
=> number of Z = 800
Q1. When 10 words are selected the number of Z can be 0 - 40 (as maximum valu of z = 400)