Hello, CAT aspirant! Are you good at solving DI problems but take time to arrive at the answers? Do you feel that you have good accuracy but lack the speed while solving DI problems? After all, acing CAT requires a fine synthesis of accuracy and speed. If you’re one such aspirant, worry not. Understanding your need, team Hitbullseye has curated this book to boost your ability to do mental calculations and improve your calculation speed.