I am greater than 15 and less than 40 If you double me I become a number that ends in 0 and of me is equal to 5 [Click to preview algebra format]
Something is missing from your question.
This may be your problem and its answer.
http://www.jiskha.com/display.cgi?id=1268689891
This is the exact way that it is written on the homework paper.
Clue 1: I am greater than 15 and less than 40.
Clue 2; if you double me, I become a number that ends in 0.
Clue 3: 1/5 of me is equal to 5.
In clue 3, part is missing in your first post.
Sorry I didn't realize I missed part of it.
OK. Anyway, the answer is in the previous post linked above.
The answer on that link would be 25 and 25 doubled isn't less than 50 it is equal to 50.
Ahh -- but the problem states: "If you double me I become a number that ends in 0
The number itself is less than 40.