Respuesta :
The vowels are A,E,I,O,U so 5 because if you add them together it’s 5
The number of possibilities for Jane for making the four letter password (either upper case or lower case) with first letter being a vowel is 1406080
What is the rule of product in combinatorics?
If a work A can be done in p ways, and another work B can be done in q ways, then both A and B can be done in [tex]p \times q[/tex] ways.
Remember that this count doesn't differentiate between order of doing A first or B first then doing other work after the first work.
Thus, doing A then B is considered same as doing B then A
We need to find the number of ways a four letter password can be made The first letter is fixed to be a vowel.
There are 10 vowels (5 of lowercase and 5 of upper case).
Thus, 10 ways of choosing the first letter.
Second letter can be any of the 52 letters(26 of lowercase and 26 of uppercase).
Similarly, third and fourth letter can be any of the 52 letters.
Thus, using the product rule, the number of ways of making the four letter password is:
[tex]N = 10 \times 52 \times 52 \times 52 = 1406080[/tex]
(the answer can be different if we consider only either lowercase letters or only upper case letters. In those cases, there would be [tex]5 \times 26^3 = 87880[/tex] ways to make such passwords).
We used product rule, since we wanted to do the choosing of all the four letters for password, and we knew the number of ways each of them can be done individually.
Thus, the number of possibilities for Jane for making the four letter password (either upper case or lower case) with first letter being a vowel is 1406080
Learn more about rule of product combinations here:
https://brainly.com/question/2763785
