I highly recommend purchasing this book. It provides a method you can follow for responding to case interview questions. If you need it ASAP then get the ebook and start learning and practicing now. You'll be glad you did. No doubt in my mind that this book is what landed me my Technology Risk audit position at EY. https://smile.amazon.com/dp/0986370746/ref=cm_sw_r_cp_apa_fabc_c8IcGbTFN54X2