I'm not too sure about what you're asking but since friction on dry concrete is 3 N while friction on icy concrete is 0.6 N, the ratio of these values is 5. This means that if you multiply the friction of icy concrete by 5 it will be equal to the friction of dry concrete. 0.6 N *5 = 3N which is equal.

Or maybe you're asking why it experiences less friction on icy concrete. It might be because:-

1. Dry concrete has a rough, porous surface that allows rubber molecules to penetrate and create a strong mechanical bond.

2. Icy concrete has a smooth, slippery surface with a thin layer of water that reduces friction and prevents rubber molecules from bonding.

3.  Icy concrete's lower temperature causes the rubber to become stiffer and less able to conform to the surface, further reducing friction.

I hope your doubt is now clear!

If not, feel free to ask again.