A connection is made consisting of resistance A in series with a parallel combination of resistances $B$ and $C$. Three resistors of value $10 Ω, 5 Ω, 2 Ω$ are provided. Consider all possible permutations of the given resistors into the positions $A, B, C$, and identify the configurations with maximum possible overall resistance, and also the ones with minimum possible overall resistance. The ratio of maximum to minimum values of the resistances (up to second decimal place) is ___________.