Control System: DC Gain
The question dictates that a Ramp input has a steady state error, therefore it must be  a Type 1 (1st order) System.

I remember this from Uni. in '70's but found on web here.
p.5 on http://www.cs.mun.ca/av/old/teaching/cs/notes/steady_quad.pdf 

From Steady state error, \$e_{ss}\$ using the final value theorem as follows;
E(s) is the Laplace transform of the error signal, e(t).   

\$e_{ss}=e(t)_{t→∞}=sE(s)_{s→0}\$

Control System errors for unity negative feedback

Step response = \$\dfrac{1}{1+k_p}\$  


this is a zero frequency response normalized to 1
unit input


Ramp response =  \$\dfrac{1}{k_v}\$  


this is a velocity dependent input rate


The overall steady state error is the sum from each input.