For Quant Researchers and Developers, a deep understanding of matrix math and optimization is mandatory.

Define it and explain how it affects model selection.

Given a positive test result for a rare disease, what is the actual probability the patient has it?

For mental math, use apps or trainers to reduce your response time.

With the rise of "Alpha Researchers," statistical significance and ML theory are now standard topics. Explain a p-value to a non-technical person.

You flip a coin until you get two heads in a row. What is the expected number of flips?

Quants must implement their ideas. Expect "LeetCode style" questions focusing on efficiency. What is the Big O complexity of QuickSort?

How does a hash map work, and what is its average lookup time?

(Questions 11–30 continue with permutations, combinations, and conditional probability scenarios.) 2. Mental Math and Brainteasers

Implement a function to find an element in a sorted array. Linked Lists: How do you detect a cycle in a linked list?