# What is a "jump response" of a filter?

I know how to determine if a filter is FIR or IIR, but I don't understand the question. What is a "jump response"?

It's a bad translation of step response, i.e., the filter's response to a unit step $$u[n]$$ at the input. Note that the step response is the convolution of the unit step with the filter's impulse response:
$$s[n]=\big(u\star h\big)[n]=\sum_{k=0}^nh[k],\qquad n\ge 0\tag{1}$$
where I've assumed causality, i.e., $$h[n]=0$$ for $$n<0$$.
From the given step response and Eq. $$(1)$$ it should be easy to derive the impulse response $$h[n]$$. You can also immediately draw a conclusion about its length. Then, by considering the symmetry of $$h[n]$$, I'm sure you know how to derive the group delay of the filter.