Word Translations -- Help!!

This topic has expert replies
Senior | Next Rank: 100 Posts
Posts: 30
Joined: Sun Jul 13, 2008 12:44 pm
Location: USA

Word Translations -- Help!!

by ramonsa » Wed May 06, 2009 4:22 pm
Hello, need help to understand this problem.

A men's baketball league assigns every player a two-digit number for the back of his jersey. If the league uses only the digits 1-5, what is the maximum number of players that can join the league such that no player has a number with a repeated digit (ex. 22), and no two players have the same number?

Thanks
Ramon
Source: — Problem Solving |

User avatar
Site Admin
Posts: 2567
Joined: Thu Jan 01, 2009 10:05 am
Thanked: 712 times
Followed by:550 members
GMAT Score:770

by DanaJ » Wed May 06, 2009 9:57 pm
Start with the tens digit: if you consider 1 the tens digit, then you've got 4 possible choices for the units digit (2, 3, 4 and 5, since you can't use 1 because it would be a repeat). This means that, in this case, you get 4 possible numbers. The same goes for the rest of the numbers: you use one of them as tens digit and the other four as units digit. This is why the total number of jerseys will be:

5*4 = 20.