You may also like

problem icon

Code to Zero

Find all 3 digit numbers such that by adding the first digit, the square of the second and the cube of the third you get the original number, for example 1 + 3^2 + 5^3 = 135.

problem icon

Dodgy Proofs

What is wrong with these dodgy proofs?

Exhaustion

Age 16 to 18 Challenge Level:

Find the positive integer solutions of the equation
 

\[ \left(1 + \frac{1}{a}\right)\left(1 + \frac{1}{b}\right) \left(1+ \frac{1}{c}\right) = 2. \]
 
 

This problem was taken from the Hungarian magazine KoMaL. There are many other challenging problems in English on the KoMal website.
The NRICH Project aims to enrich the mathematical experiences of all learners. To support this aim, members of the NRICH team work in a wide range of capacities, including providing professional development for teachers wishing to embed rich mathematical tasks into everyday classroom practice.
Copyright © 1997 - 2018. University of Cambridge. All rights reserved.
NRICH is part of the family of activities in the Millennium Mathematics Project.