# probability

posted by .

you are to set up a code of consisting of three letters (A to Z) and five numbers (0 to 9).

a) how many codes are possible if the letters and numbers can be repeated?
b) how many codes are possible if each letter and digit can be only used once?
c) how many codes are possible if each code begins with an A and if the digits cannot be repeated?

• probability -

Try some of the following probability tutorials:

http://search.yahoo.com/search?fr=mcafee&p=probability+tutorials

Sra

• permutations -

B) it would be 26P4 (the number of permutations for the letters) x 9P3 (number of permutations for the digits)

You times because for each letter permutation the can be 9P3 digit permutations.

## Respond to this Question

 First Name School Subject Your Answer

## Similar Questions

1. ### math

Suppose a code consist of two letters followed by a digit. Find the number of (a) Codes (b) Codes with distinct letters (c) Codes with the same letters
2. ### math

Suppose a code consist of two letters followed by a digit. Find the number of (a) Codes (b) Codes with distinct letters (c) Codes with the same letters.
3. ### maths permutation and combination

Your password for a given website is made up of three letters followed by four numbers. Find the number of possible passwords if there are no restrictions on what three letters and what four numbers can be used.
4. ### math

a book club assigns to each member a membership number that consists of 2 letters followed by 4 numbers. how many different membership numbers are possible. tne membership numbers look like XXxxxx where X are letters and x are letters.
5. ### discrete math

How many strings of five uppercase English letters are there (a) that start or end with the letters BO (in the order), if letters can be repeated?
6. ### Permutations

A valid password on a Web site contains 3 letters (A-Z, 26 total), followed by 3 digits (0-9). Letters and numbers can be repeated. The number of possible passwords equals _____. A. 26*25*24+10*9*8 B. 26^3+10^3 C. 26^3*10^3 D.26*25*24*10*9*8
7. ### Permutations

A valid password on a Web site contains 3 letters (A-Z, 26 total), followed by 3 digits (0-9). Letters and numbers can be repeated. The number of possible passwords equals _____. A. 26*25*24+10*9*8 B. 26^3+10^3 C. 26^3*10^3 D.26*25*24*10*9*8
8. ### Math

1.) A security code has seven characters. Each code begins with two digits, then two letters, and finally three digits. the number of distinct security codes possible if repetition is allowed?
9. ### math please hurry

A secret code must consist of three capital letters followed by a digit. Letters cannot be repeated. How many secret codes are possible?
10. ### geography

Serial numbers for a product are to be made using 3 letters followed by 4 numbers. If the letters are to be taken from the first 8 letters of the alphabet with repeats possible and the numbers are taken from the digits 0 through 9 …

More Similar Questions