Library / UKMT Junior Mathematical Challenge /248 of 274

UKMT Junior Mathematical Challenge, 2021

Number theory Difficulty 3.0 AMC 10/12 Find the answer United Kingdom

Each cell in the crossnumber below contains a single non-zero digit. The answer to each clue is a two-digit number. Clues Across: 1. A square, 3. An odd square. Down: 1. A square, 2. A square. What is the value of $x$ ?

(A) $1$ (B) $3$ (C) $5$ (D) $7$ (E) $9$

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.