Solution Found!
How many 5-digit numbers can be formed from the integers
Chapter 1, Problem 10STE(choose chapter or problem)
QUESTION:
Problem 10STE
How many 5-digit numbers can be formed from the integers 1,2,... ,9 if no digit can appear more than twice? (For instance, 41434 is not allowed.)
Questions & Answers
QUESTION:
Problem 10STE
How many 5-digit numbers can be formed from the integers 1,2,... ,9 if no digit can appear more than twice? (For instance, 41434 is not allowed.)
ANSWER:
Step 1 of 2
Our goal is:
We need to find how many 5-digit numbers can be formed from the integers 1,2,... ,9 if no digit can appear more than twice.
We know that there are 3 cases.