The inductive effect is caused by the electrostatic nature of the groups adjacent to the carbocation. So, if I have an electron withdrawing group (e.g F), the carbocation is going to be made more postive and therefore be more unstable. If I have an electron releasing group (like Me), my carbocation is going to be less postive and more stable.
Hyperconjugation refers to the electrons in a sigma bond interacting with either an adjacent non-bonding p-orbital, antibonding or filled pi bond. This effect requires the correct alignment of the orbitals, and the stabilisation of the carbocation occurs as it is made less postive by the electrons from the sigma bond (of methyl C-H).