Find the smallest positive integer the first digit of which is 1 and which has the property that, if this digit is transferred to the end of the number, the number is tripled.

If you think you have the right answer, put your answer at the end of the following URL followed by .aspx to see if you are right and be awarded with an extension problem!

http://www.kcl.ac.uk/mathsschool/Weekly-Maths-Challenge/

(so if for example you think the answer is 1592 then go to http://www.kcl.ac.uk/mathsschool/Weekly-Maths-Challenge/1592.aspx . The link will only work if you are correct!)