Linear equations and inequalities

Consider a coil composed from a ferrite core and a wire winding. The mass of the core is $2\mathrm{kg}$. The material for the wire is such that the mass of the wire of the length $30\mathrm{m}$ is bigger than the mass of the wire of the length $10\mathrm{m}$ together with the ferrite core. In the following list identify a possible mass of one meter of the wire.