Question

Hello. I need some help

There is a code, which is made by two letters from 23 letters and 3 numbers from numbers 2,3,4. This code doesnt exist, when all three numbers in a code are the same. How many ways a code can be made. How I think:

The letters can be:
23*23=529
Numbers:
3*3*2=18

But the answer is 12144. Can anyone help me?

Answer 1

Omg! I have forgotten to say that there is made of 5signs

Answer 2

i thought we have "26" alphabets

Answer 3

Yeah

Answer 4

Well, it is how the problem sounds. We can take any number, I need a way how to solve this problem

Answer 5

and, actually, I am NOT from USA/UK and our language doesnt have Q,W,X so it is why 23:))

Answer 6

so, any tips?

Answer 7

two letters from 23 = 23*22
3 letters = 3*2*1 = 6

Answer 8

how many signs you need in the code?

Answer 9

5

Answer 10

"5" available and you use how many of them?

Answer 11

and why it is 3*2*1 if it can be two same numbers?

Answer 12

all of them

Answer 13

yes. the order.. you can arrange them in 6 ways

Answer 14

impossible..
all "5" signs? your answer uses one of "4" signs

Answer 15

if "5" is correct, then the answer will not end with a "4" at its units place.

Answer 16

why it is not 3*3*2? :) You can use TWO same numbers, but you cant use three same numbers. For example:
You CAN use a code like this AB 233, but you CANT use a code AB 333

Answer 17

could you post the exact wordings of the question.

Answer 18

so, it is then
alphabets = 23*22
numbers = 3^3-3 = 24

total combinations = 23*22*24

Answer 19

Can you explain me?

Answer 20

alphabets = no repetition = 23*22
kapeesh?

Answer 21

number of ways of arranging all "3" numbers = 3^3
but no repetition -> so -> 3^3-3

Answer 22

well, the problem doesnt say letters cannot repeat:) But the answer is correct, thank you.

Answer 23

I know. and the signs are unacconted for too. but this is the only way I can explain that number you gave as the answer!

Answer 24

oh,okay:) Thank you.

Answer 25

yer welcome :D