Jump Trading Interview Questions

How do you reverse a linked list?

What is the expected value when rolling a fair six-sided die?

A fair six-sided die is rolled twice. What is the expected value of the larger number obtained?

We take turns flipping a coin; the first one to get a tail wins the game. Is it a fair game? If not, what is the probability of the first player winning?

Let X and Y be independent standard normal random variables (mean 0, variance 1). What is the probability that X is greater than 5 times Y, i.e., P(X > 5Y)?

Given that a^2 + b^2 = c^2 and a + b + c = 40, where a, b, and c are positive integers, what are the values of a, b, and c?

Reverse a linked list without using loops.

There are 4 balls in a bag: 2 red and 2 black. Randomly pick 2 balls; paint the second ball to the color of the first ball. What is the expected number of times this operation must be repeated until all the balls have the same color?

Let U₁, U₂, ... be independent uniform (0,1) random variables. Define N = min{ n : sum_{i=1}^n Uᵢ > 1 }. What is E[N]?

How many zeros are there in 100 factorial (100!)?

What is a virtual destructor?

Suppose a collection of n random variables have all pairwise correlations equal to c. Find, with proof, the range of possible values of c.

You have 5 unknown numbers. When selecting any two out of these five, there are 10 possible pairs. You are given the sums of all these 10 pairs. Using this information, find the original 5 numbers.