Oxford & Cambridge

Puzzles, proof, and the shape of how you think.

CS interviews at both universities lean on problems you haven't seen before: induction, recursion, combinatorics, and 'talk me through your thinking' prompts. The interviewer wants to see how you set a problem up, how you handle being stuck, and whether you can recover from a wrong path.

You choose Oxford or Cambridge when you sign up, and the interviewer tunes its style to match. MockLabs for Oxbridge is not affiliated with either university.

What we ask

Questions in the shape of the real thing.

Drawn from publicly reported interview content and the kind of reasoning that comes up year after year. The interviewer will follow up until your reasoning holds.

Induction

Prove that the sum of the first n odd numbers is n².

Recursion

Define a recursive function for the number of ways to climb n stairs taking 1 or 2 at a time.

Puzzles

I have a 3-litre jug and a 5-litre jug. Can I measure exactly 4 litres?

Combinatorics

How many ways are there to choose 3 people from 10 if one specific pair refuses to be in the group together?

Algorithms

Why is merge sort O(n log n)? Walk me through the analysis.

Logic

If P implies Q, and Q is false, what can we say about P?

One realistic mock takes ~30 minutes.

Pick a phase to practise in isolation, or run a full mock end-to-end.

Get started