Below is a list of tips and recommended resources to assist in practicing quantitative case interview questions.
Standardized Testing Practice Books:
Standardized test prep books have example quantitative questions I would suggest looking in GMAT, GRE preparation books – and specifically look for the section that’s most similar to these types of questions.
GRE Prep Plus 2019: Practice Tests + Proven Strategies + Online + Video + Mobile (Kaplan Test Prep)
GRE Math Prep Course (Nova’s GRE Prep Course)
CliffsNotes Math Review for Standardized Tests
Online Practice Resources:
CaseInterview.com: