An endless ladder of resistors
A ladder circuit repeats forever: each section has a 1 Ω resistor along the top rail, then a 1 Ω rung across to the bottom rail. What is the resistance between the two terminals at the start?
This problem is in the rehearsal, with its hints, follow-ups and Mia's marks. Try the free Engineering problem first.
Oxbridge Interview Rehearsal: two subjects
£249 once. No VAT is charged.
Introductory price £249 until 31 December, then £399.
Rehearse every problem in two subjects you choose, with hints, follow-ups and Mia's marks, for 12 months.
- All 8 problems in each of your two subjects, chosen after you pay
- Hints when you are stuck, then the tutor's follow-up questions
- Mia's marks on up to 60 attempts a day, within a fair-use allowance for each interview season: thinking aloud, using hints, checking, reasoning
- Your next problem picked from your weakest skill
- Your latest 300 attempts saved, with re-attempts side by side
Access for 12 months, until 6 November 2027. Choose your subjects after paying, on a free account. Full refund within 14 days, for any reason.
By paying you agree to our Terms and get access straight away, which ends your 14-day cancellation right. Your full refund within 14 days, for any reason, still applies.Oxbridge Interview Rehearsal: all subjects
£349 once. No VAT is charged.
Introductory price £349 until 31 December, then £499.
Every problem in all seven subjects, for joint courses and for practising beyond your own subject.
- All 56 problems: Maths, Computer Science, Engineering, Physics, Economics, Law and PPE
- Hints when you are stuck, then the tutor's follow-up questions
- Mia's marks on up to 60 attempts a day, within a fair-use allowance for each interview season: thinking aloud, using hints, checking, reasoning
- Your next problem picked from your weakest skill
- Your latest 300 attempts saved, with re-attempts side by side
Access for 12 months, until 6 November 2027. Use it on a free account. Full refund within 14 days, for any reason.
By paying you agree to our Terms and get access straight away, which ends your 14-day cancellation right. Your full refund within 14 days, for any reason, still applies.