What is the Number?
Date: 29 Mar 1995 10:05:01 -0500 From: JOSEPH CAPASSO Subject: help I'm in 7th grade, need someone to explain how to solve this simple word problem. "You know that a certain 5-digit number is a power of 7 and that its ones digit also is 7. What is the number?" If you can help me, I have a couple more.... Thanks Joe
Date: 29 Mar 1995 13:27:31 -0500 From: Dr. Ken Subject: Re: help Hello there! Well, I think that the easiest way to solve this problem is probably to start writing down the powers of 7: 7, 49, 343, etc. How many of them have five digits? It may take a minute or two to write them down, but once you do that, it will become pretty clear what the answer is. Write back if you need more help! -Ken "Dr." Math
Search the Dr. Math Library:
Ask Dr. MathTM
© 1994-2013 The Math Forum