# Arranging roses

Ten roses are arranged in two rows of five flowers each:

What is the minimum number of roses that need to be moved to arrange the flowers into five rows of four roses each?

Similar puzzle: Plant 9 trees in 10 rows of 3

• Just to clarify, the rows cannot be collinear like the puzzle you posted in the link? Commented Mar 29, 2016 at 22:37
• Yeah, someone should add that caveat. The original image already contains 10 unique rows of 4 roses each, leaving '0' as the correct answer. Commented Mar 30, 2016 at 1:20

I can solve it by moving only

4 roses (I don't think we can do better)

My drawing :

in green the original roses, in red the new ones

• I have not been able to find a way to use less than 4. Good going! Commented Mar 30, 2016 at 2:11

# 6.

As you can see, it is a (badly drawn) star, with 5 rows of 4 roses.

• Why would you need to move 10 roses if there are 10? Surely one of them can stay put. And in your drawing 4 of them have actually not moved. Commented Mar 29, 2016 at 23:05