Math
posted by SkaterGirl .
Find, with justi cation, the smallest integer whose rst digit is 1 and which has the property
that if this digit is transferred to the end of the number, then the number is tripled

A method of solution can be found here:
http://people.missouristate.edu/lesreid/Ans03_96.html
It has to be understood that the "1" is moved to the end of the number, not switched with the last digit.
It is a rather large number, as you will see. 
The answer given at the site I provided above is 142857. The "switched" number is 428571