Jane Street Quant Interview Questions | Glassdoor

# Jane Street Quant Interview Questions

## Interviews at Jane Street

9 Interview Reviews

Experience
33%
56%
11%

### Getting an Interview   9 Interview Reviews

Getting an Interview
80%
20%

3.4
Average

Hard
Average
Easy

## Quant Interview

No Offer
Positive Experience
Average Interview

Application

The process took 1 day. I interviewed at Jane Street (New York, NY) in September 2010.

Interview

I applied online. I was asked to be interviewed days later. The first questions are calculations such as 145x23. Later come 2 probability questions and two brainteasers. The interviewer is a male with no foreign accent. He sounds friendly and patient.

Interview Questions

• find a subset of {1,2,3,...,30} so that numbers in that subset is coprime to each other.   6 Answers

## Quant Interview

No Offer
Neutral Experience
Difficult Interview

Application

I applied online. The process took 1 day. I interviewed at Jane Street (New York, NY) in October 2010.

Interview

The first two rounds of interviews were with researchers. They were pretty nice guys at least it seemed that way during the phone interview. They asked me to walk through my resume first. (Just be confident with whatever you put on your resume.) At the end, you asked simple brain teaser. I failed the third round phone interview with a trader. I got stuck at one problem and that trader lost his patience on me.

Interview Questions

• estimate how many gallons of gas are consumed in US per week   5 Answers
• suppose you live in middle town, your mom lives in downtown while your girl friend lives in uptown. You take subway to have dinner with either your mom or your girl friend every night. You always the first train that arrives at the station. why do you end up with have dinner with your girl friend 90% of the times? assume the uptown and downtown train run at the same intervals.   6 Answers
• suppose you, player A, player B are in a tennis tournament. Player A has a better chance of beating you than player B does. If you would like to maximize your chance of winning two games in a row, which sequence would you prefer, ABA or BAB?   4 Answers
• suppose you have a perfectly round disk. You put three legs randomly on this disk to form a table. Supposing the legs are perfectly perpendicular to the disk and are attached to the disk firmly, what is chance that the table will not fall when you flip the disk or in other word when you put the table to stand on its legs?   26 Answers

## Quant Interview

No Offer
Neutral Experience
Average Interview

Application

The process took 1 day. I interviewed at Jane Street (New York, NY) in November 2011.

Interview

Standard quant phone interview. Thirty minutes and a few brainteasers.

Interview Questions

• Unfair coin with P(H) = 1/3 and P(T) = 2/3.
a) How to make an event with 50% probability?
b) Expected number of flips until a realization occurs?
c) Can you create a strategy to reduce the number of flips necessary?
d) Can you create a strategy to reduce the number of flips necessary for an unfair coin with any bias?   7 Answers
• 2) Alice and Bob play baseball for two periods. Can Alice have a better batting average than Bob in the first period but Bob have a better batting average overall?   1 Answer
3.

## Quant Interview

No Offer
Negative Experience
Difficult Interview

Application

I applied online. The process took 2 weeks. I interviewed at Jane Street (San Jose, CA) in January 2014.

Interview

Difficult math contest questions. The interviewer was pleasant. He asked lots of questions about statistics and probability. He was listening for the thought process on everything, even if I wasn't sure of the answer

Interview Questions

4.

## Quant Interview

No Offer
Neutral Experience
Average Interview

Application

I applied through college or university. The process took 1 day. I interviewed at Jane Street (Hong Kong (Hong Kong)) in January 2012.

Interview

Need to be analytic

Interview Questions

5.

## Quant Interview

No Offer
Neutral Experience
Average Interview

Application

I applied online. The process took 1 day. I interviewed at Jane Street in September 2010.

Interview

phone interview with probability brainteaser and a bit of discussion on my background.

Interview Questions

• Sitting on the side of the road you observe that at least one car drive by every 20 minutes. What is the probability to see exactly one car in 5 minutes ?   1 Answer

6.

## Quant Interview

No Offer
Neutral Experience
Difficult Interview

Application

I applied online. The process took 1 day. I interviewed at Jane Street in November 2011.

Interview

Filled up the online application and got an email scheduling a phone interview. They asked probability and statistics questions such as coin flipping, dice rolling, etc. and also some mental math questions. Overall the questions weren't very difficult but since you couldn't use a pen and paper it was a lil tricky.

Interview Questions

7.

## Quant Interview

No Offer
Positive Experience
Average Interview

Application

The process took 4 weeks. I interviewed at Jane Street in December 2015.

Interview

Sent my cv off and a few weeks after I had a telephone interview. The interviewer was very friendly and helped me through when I had a few mind blocks. I think I went in too nervous about how hard it was going to be and couldn't think properly! Looking back on it, it was not a hard interview, especially if you read the questions on this site.

Interview Questions

• Sum of odd numbers up to 50 and a simple bases rule question.   Answer Question
8.

## Quant Interview

No Offer
Positive Experience
Difficult Interview

Interview

Supposedly 4 phone round interviews, followed by an in-person interview. Made it to the third phone round but was rejected after. First was basic probability and gets progressively harder through the rounds.

Interview Questions

• 3x3x3 cube; paint the outside. Cut cube up into 1x1x1 cubes. Pick a random 1x1x1 cube and roll, what is the probability a painted side is face up?   2 Answers

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