First, the standard way to measure heat is in Joules, so convert kJ to J by multiplying by 1000 (since there are 1000 kilojoules in one Joule). This gives you 520J. Next, you will need the following formula: Q = m × C × ΔT, where Q is heat, m is mass, C is specific heat, and ΔT is change in temperature. Plug in all the values given and solve algebraically for C, the specific heat!
(520) = (17.0)(C)(3.6)
520 = (61.2)(C)
8.5 = C
Remember sig figs! In the question, the value with the lowest number of significant figures has two, so your answer must have two! Also, remember units! Specific heat is measure in J/g•⁰C. So, the answer is 8.5 J/g•⁰C. Hope that helps!