We can use a dll with a different version by using which of following tag in web config.

182.

BindingRedirect

DependentAssembly

AssemblyIdentity

both a and c

both a and b

When you build a .NET Framework application against a strong-named assembly, the application uses that version of the assembly at run time by default, even if a new version is available. However, you can configure the application to run against a newer version of the assembly