Free Interview Resources
Free practice questions, preparation advice, and expert insights for Computer Science and Philosophy interviews at Oxford.
Real Computer Science and Philosophy interview questions in the style Oxford asks. Try answering each one aloud before you reveal the hint.
You have ten boxes, ten colours of blocks and one hundred blocks in total. Show that the blocks can be packed so that every box contains no more than two colours.
Problem-Solving
Hint
Try filling one box by eliminating a colour, then reduce the problem to fewer boxes and colours.
A function on the interval from 0 to 1 rises to a single maximum and then falls. If you can query values of the function, how would you locate the maximum, and what accuracy is possible with only ten queries?
Problem-Solving
Hint
Compare this with binary or ternary search, but notice what information each query gives.
In a two-player chocolate-bar game with one poisoned square, players alternately break off and eat a straight-line piece. After seeing the bar, should you move first or second, and what is your strategy?
Problem-Solving
Hint
Start with a one-row bar, then place the poisoned square in a corner and look for a symmetry or pairing strategy.
A frog moves from pad 0 to pad 10, jumping either one or two pads each time. How many different jump sequences get it to pad 10?
Problem-Solving
Hint
Let the number of routes to pad n depend on the previous two pads.
Given a list of just under one million distinct integers from 0 to 999,999, how could you find a missing integer in reasonable time?
Problem-Solving
Hint
Think about memory, sorting, marking seen values, or using a sum or XOR-style invariant.
Tutorial-style interviews with subject-specific problems, often involving unfamiliar material.
Oxford interviews typically take place at the college you applied to. You will usually have two or three interviews of around 20-30 minutes each, sometimes at different colleges if you are pooled. The atmosphere is meant to resemble a tutorial: the interviewer gives you a problem and watches how you reason through it.
Interview Invitation
Late Nov
Arrival to Interview
Early Dec
Technical Question
Mid Dec
Decision
Early Jan
Interview Invitation
Late Nov
Arrival to Interview
Early Dec
Technical Question
Mid Dec
Decision
Early Jan
Seven perfectly logical pirates must divide 100 coins under a majority-vote rule where failed proposals remove the proposer. What offer should the most senior pirate make?
midHint
Solve the game backwards from two pirates, then add pirates one at a time.
For which square values of n can you choose half of the natural numbers below n so that none is a square and no two chosen numbers sum to n?
hardHint
Pair numbers that add to n, then ask which pairs are made unusable by square numbers.
Find the smallest positive integer ending in 6 such that moving that final digit to the front makes a number four times as large.
midHint
Represent the unknown number as 10a+6 and track how many digits a has.
Given a ten-digit number, delete three digits while preserving order to make the largest possible seven-digit number; then give an efficient general strategy for deleting k digits from an n-digit number.
midHint
At each position, ask how far ahead you may look while still leaving enough digits to finish.
Draw all increasing rooted labelled trees with four vertices, then generalise to count increasing trees on n vertices.
hardHint
Build a tree with n+1 vertices by adding the largest label as a new child of an existing vertex.
Positive numbers a1 to a8 add to 27. Minimise the sum of the eight hypotenuse-like terms below, and decide whether the minimising values can be rational.
hardHint
View the expression geometrically as a broken path and compare it with the straight-line distance.
An urn starts with 23 white beans and 34 black beans. Two beans are removed repeatedly; equal colours are replaced by a black bean and different colours by a white bean. What colour is the final bean?
entryHint
Look for a quantity whose parity never changes.
Starting with the word PQ and using three rewrite rules involving P, Q and R, decide which sample words can be produced and describe a general decision method.
hardHint
Try to find an invariant under the rewrite rules, rather than generating words blindly.
For the function below, find a lower bound valid for every s greater than 1 and explain why s = 1 is excluded.
hardHint
Compare the series with familiar divergent and convergent series, and separate the first term from the tail.
What is involved in blaming someone?
entryHint
Separate the judgement that someone did wrong from emotions such as anger or resentment, then test each proposal with counterexamples.
Sort out the differences between lying, deceiving and misleading.
entryHint
Use examples in which someone says something true but still creates a false belief.
Are our deaths bad for us?
midHint
Separate the process of dying from the state of being dead, then ask who or what can be harmed.
Can a philosophy interview fairly ask you to reason about a puzzle, argument or moral scenario you have not studied before?
entryHint
Focus on how the applicant reasons, responds to objections and changes view, not on prior knowledge.
If a machine could give you all the enjoyable and valuable experiences you wanted, while hiding the fact that they were not real, would you plug in for life?
midHint
Distinguish pleasure, value, reality, achievement and autonomy before deciding.
Is there a moral reason not to take a flight if the plane will fly whether or not you personally board it?
midHint
Ask whether individual responsibility depends only on making a difference to the final outcome.
12+ weeks
8-12 weeks
4-6 weeks
1-2 weeks
the week of
Unlock the full guide
Free Resource
The Complete Oxford Computer Science and Philosophy Interview Guide
Enter your email to unlock the full question bank, worked approaches, a week-by-week prep roadmap, and the mistakes that cost offers.
Practice with a Oxford Computer Science and Philosophy graduate who's been through it.
Book Mock Interview →Watch & Learn
Shows the style of a CS problem-solving interview for Oxford applicants.
3Blue1Brown is listed by Oxford CS as a mathematical activity resource; this video supports AI conceptual understanding.
Useful high-level orientation across theoretical and practical areas before choosing deeper reading.
Computerphile is listed by Oxford CS, and computability connects directly to the course’s Alan Turing content.
Helps applicants practise the CS&P bridge between computation, mind and intelligence.
All videos are the property of their respective creators.
Further Reading
by Anany Levitin and Maria Levitin
Oxford Computer Science lists it as a source of algorithmic puzzle-solving practice.
by Margaret A. Boden
Useful for the AI, mind and philosophy-of-computation overlap that suits CS&P.
by Charles Petzold
Oxford lists it as an accessible way into how hardware and software represent information.
by Daniel Velleman
Oxford recommends it for logical and discrete-maths preparation, especially for applicants without Further Maths.
by Raymond M. Smullyan
Oxford lists it as logic/metalogic puzzle practice with philosophical flavour.
by UAT-UK
Primary preparation source for the required admissions test.
by University of Oxford Mathematical Institute
Explains the Oxford-specific use, format and preparation approach for TMUA.
by University of Oxford Department of Computer Science
Closest official model for CS interview problem style.
by University of Oxford
Includes official Computer Science and Philosophy/PPE-style examples with tutor commentary.
by University of Oxford Department of Computer Science
Official list of books, mathematical activities, websites and CS&P applicant suggestions.