Wednesday, August 15, 2007

Problem of the Week #1

A palindrome is a word or phrase that is spelled the same forward and backward. My favorite palindromes are "I, madam, I made radio. So I dared! Am I mad, am I?" and "Rats live on no evil star."

A palindrome number is one which would have the same value if it were turned front to back. The numbers 12,321 and 5,775 are examples.

Problem: Find a palindrome number x such that

where if A is the first digit of x, B is the second digit, and C is the third digit of x, then

and

36 comments:

Mrs. Cooper said...

I know a good way to start...A can not be a 9 or 8 because 9 is not less than 8 and even though 8 is less than 9, 9 is not less tahn any thing else. That wouldn't leave anything possible for the third digit. (89?)

Sarah said...

So, doesn't "A" have to be only 7 at the most since "A" is less than two other numbers?

Sarah said...

I mean "A" has to be 7 OR LESS...

Mrs. Cooper said...

So maybe I can start trying numbers that begin with 6. (And then they would also have to end in a 6 if they are a palindrome)

Sarah said...

Now I have a question: If I wanted to represent the number x with the digits A,B and C, would it be ABCCBA?

Also, couldn't A be 7 actually? Why are you starting with numbers that start with 6?

OK, so that was really TWO questions...

Mrs. Cooper said...

YES! That is what I think too :)

Sarah said...

Do you think there is more than one answer for this question?

Mrs. Cooper said...

maybe?

Sarah said...

Well, I know that 3*3 + 4*4 is 9+16=25 which is 5*5 so that is an option for A,B and C but is that the only set of numbers that will work?

jessie said...

This is a pretty hard problem, you really have to sit and think.

anonymous said...

A chart can gelp to figure it out.

anonymous said...

and i dont think that there is more than one answer

Mrs. Cooper said...

I think it is 345,543. Does that check with all of the clues?

Sarah said...

That's what I got too!

anonymous said...

i also think that's the answer.

sivan said...

cant it also be 545,545?

Sarah said...

It is a palindrome, Sivan, but it doesn't satisfy one of the requirements. Do you see which one?

scotty said...

this is confusing

scotty said...

could it 899998?

jose-gonzalez said...

let me think

matthew said...

the numbers at the beginning and end have to be the same

jessie said...

ok

jessie said...

i just double-checked and it's right!!!! :)

Anonymous said...

this is a cool problem dont you agree

Jonathan said...

very very confusing

Anonymous said...

it is also very hard

Sarah said...

You really have to be a smart cookie for that problem.

Sarah said...

It is so confusing u wouldnt know where to start?!

anonymous said...

dont start trying all kinds of random numbers...
i started doing that and didnt get anywhere.

anonymous said...

also remeber that the first number has to be smaller than the second number and that the second number has to be smaller than the third number. 656,656 wouldn;t work because 6 is bigger than 5.

anonymous said...

344,443 wouldn't work either because 4 and 4 r the same numbers.

jeremy said...

it's to hard

Sarah said...

I found out that the answer really is 345543 it all works out. See for yourself. It took a good space of scrap paper but it finally fit. I totally agree with Mrs. Cooper.
It is hard but possible...

Sarah said...

I never thought I would get it but I did. yahoooo

Anonymous said...

I think that the answer is also 345543 so good job to every body that got 345543

Sarah said...

Man we all wonder why they are so hard in the first place. When I was trying to figure it out it hurt my head. Lots of brain work....