# Different number of numbers

• Apr 16th 2007, 10:37 AM
Amy
Different number of numbers
A telephone number consists of seven digits. The first three representing the exchange. How many different telephone numbers are possible within the 537 exchange?

in this case repetition of numbers is possible.

So, How can I do this?
• Apr 16th 2007, 11:03 AM
Soroban
Hello, Amy!

Quote:

A telephone number consists of seven digits.
The first three representing the exchange.
How many different telephone numbers are possible within the 537 exchange?
In this case repetition of numbers is possible.

So, How can I do this?

Instead of waiting for Divine Inspiration, try Thinking.

How many 4-digit combinations are possible?

Well, they range from 0000 to 9999, right?

That makes a total of . . . um . . .

• Apr 16th 2007, 07:35 PM
CaptainBlack
Quote:

Originally Posted by Soroban
Hello, Amy!

Instead of waiting for Divine Inspiration, try Thinking.

How many 4-digit combinations are possible?

Well, they range from 0000 to 9999, right?

That makes a total of . . . um . . .

Well total means add so:

0000 + 9999 = 9999

:cool: RonL
• Apr 17th 2007, 12:38 PM
Amy
How 0000+9999=9999 :confused:

I thought it was 10*10*10*10=10000
• Apr 17th 2007, 12:40 PM
CaptainBlack
Quote:

Originally Posted by Amy
How 0000+9999=9999 :confused:

I thought it was 10*10*10*10=10000

Its a joke. Range from 0000 to 9999 makes a total - see a sort of joke.

RonL