Library / UKMT Junior Kangaroo /99 of 243

UKMT Junior Kangaroo, 2026

Combinatorics Difficulty 2.0 Junior Find the answer United Kingdom

The diagram shows a lake containing 10 islands linked with 12 bridges. What is the smallest number of bridges that would need to be closed to prevent anyone walking from island P to island Q?

(A) $1$ (B) $2$ (C) $3$ (D) $4$ (E) $5$

Figure for this problem

We don't reproduce this publisher's solutions. Their own solution is here — work the problem first.

Want a route through all this instead of an archive? The track puts 2,604 problems in a working order, from Junior Challenge level to the IMO shortlist.

Source: UK Mathematics Trust, licensed © UK Mathematics Trust; past papers published free at ukmt.org.uk. Statement reproduced verbatim; metadata (topic, difficulty) added by this project. Solutions are the publisher's, linked not copied.