Volume 39
, Issue 2


This issue of Parabola contains two articles on symmetry.

What do the following objects have in common? The set of complex numbers of modulus one; an equilateral triangle; a water molecule.

Many of us have been delighted with the extraordinary geometrical forms that can be constructed with the seven pieces of the rectangular or the square tangrams.

A cow is inside a square field. Its distances from the nearest three corners are 30m, 40m and 50m. What is its distance to the furthest corner, and what is the size of the field?

Prize Winners- Junior Division

First Prize

Yu Heng Lau              James Ruse Agricultural High School

Q1141 In the 2003 cricket XI there were 7 boys who had been in the 2002 XI, and in the 2002 XI there were 8 boys who had been in the 2001 XI. What is the least number who have been in all three XIs?

Q1131 Suppose $A$ and $B$ are two equally strong tennis players. Is it more probable that $A$ will beat $B$ in three sets out of 4 or in 5 sets out of eight?