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:

Khan Academy

Magoosh Resources