The Quant Zone

Four people must cross a dark, narrow tunnel with only one torch.
Only two can walk at a time, and each person walks at a different speed.

Sounds simple? It isn’t.

In this video, we break down the famous Tunnel and Torch puzzle, starting with a common but inefficient approach—and then reveal the optimal strategy that minimizes total time. This problem tests logical thinking, optimization, and interview-style reasoning, making it a favorite in quant, tech, and consulting interviews.

If you enjoy brain teasers, probability puzzles, and sharp problem-solving challenges, this one will stretch your thinking.

In this video, we solve the classic Two Glass Balls and 100 Floors brain teaser — a problem frequently asked in quant, software engineering, and data science interviews.

You’re given:
• A 100-floor building
• Two identical glass balls
• A hidden floor Y where the balls start breaking

The challenge is to find Y with the minimum number of drops in the worst case.

We break down:
• Why naïve and binary-search strategies fail
• The optimal decreasing-step strategy
• How the solution guarantees the answer in just 14 drops
• The intuition behind the formula N(N+1)/2

Perfect for:
Quant interview prep • FAANG interviews • Brain teaser practice • Algorithm intuition

If you enjoy solving interview-style puzzles, consider subscribing for more quant and problem-solving content.

The Probability Puzzle Everyone Gets Wrong — Pancake Edition

Link to Full video: https://youtu.be/lKWbDBeKiAo

Full video: https://youtu.be/PyFhHvjdDfo

Link to Full Video: https://youtube.com/shorts/lCb6eCykSSo