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.

Solve the following inequality: $$(5+2x)\cdot (-3)+16<20-6x$$

Solve the following inequality. $$-3x>6$$

Assuming $x\in (0;3]$, solve the following inequality. $$6-2x\le 3x-4$$