Desmond MacHale was born in 1946 in Castlebar, County Mayo, Ireland. He earned his B.Sc. and M.Sc. degrees in Mathematical Science at University College Galway. In 1972, he was awarded a Ph.D. degree in Group Theory at the University of Keele in the UK under the supervision of Dr. Hans Liebeck. He taught mathematics for forty years at University College Cork in Ireland, rising to the rank of Associate Professor. He has over a hundred research articles published in refereed mathematical journals and his interests lie mainly in abstract algebra (groups and rings) but he has also published articles on geometric dissections, number theory, Euclidean geometry, trigonometry and a book on mathematical humour (Comic Sections Plus). Both as a student and teacher, he has won many prizes for his work on the popularisation of mathematics. He is currently Emeritus Professor of Mathematics at University College Cork.

In 1984 he set up the Superbrain Examination open to all students of UCC and later the Irish Intervarsity Mathematics Competition. He has written four biographical books on George Boole who was the first professor of mathematics in Cork from 1849 to 1864. These are George Boole His Life and Work (2014); New Light on George Boole (with Yvonne Cohen) (2018); The Poetry of George Boole( 2021); and Simply Boole (with Yvonne Cohen) to appear. In 2015 he was awarded an honorary doctorate in Literature by the National University of Ireland for his work on George Boole. He has written over a dozen books of Lateral Thinking puzzles with Paul Sloane and many other books of mathematical puzzles, riddles and jokes-over eighty books in all.

Among Des MacHale's other interests are Geology (in which he has a diploma), puzzles of all sorts, words, music especially classical and Irish, photography,

He believes that mathematics is like an infinite goldmine-the more gold you dig out, the more there is to find.

Problems and Solutions

1. Number Theory.
2. Primes and Divisibility.
3. Geometry.
4. Trigonometry.
5. Probability.
6. Combinatorics.
7. Dissections.
8. Matchsticks and Coins.
9. Logic.
10. Maxima and Minima.
11. Calculus and Analysis.
12. A Mixed Bag.