Answer:
The size of the sample is 840.
The probability that the first three letters of the four-letter code are vowels is=\frac{1}{35}=
35
1
Step-by-step explanation:
Th total number of letters given to form code of 4 letters = 7
Since, the order of the letters in the code matters, which means there is no repetition.
The total number of ways to form the code size =7*6*5*4=8407∗6∗5∗4=840
Therefore, The size of the sample is 840.
Since, there are 3 vowels and rest of 4 letters are consonant.
The number of ways to form code such that the first three letters of the four-letter code are vowels =3\times2\times1\times4=243×2×1×4=24
The probability that the first three letters of the four-letter code are vowels is
=\frac{24}{840}=\frac{1}{35}
840
24
=
35
1