Average emf in a coil

A coil of $150$ turns, each of area $12\mathrm{c}{\mathrm{m}}^2$, has its axis parallel to a uniform magnetic field that changes from $0.20\mathrm{T}$ to $0.80\mathrm{T}$ in $30\mathrm{ms}$. Compute the magnitude of the average emf induced in the coil.