Volume 17
, Issue 1

1981

We received an interesting letter from one of our readers, S.J. Cohen, who has found a way of generating sequences of Pythagorean Triangles by means of certain irrational square roots.

In the 1980 H.S.C paper Question 9 in the 3 unit paper and Question 2 part (ii) in the 4 unit paper concerned polynomials which seemed to prove somewhat troublesome for students.

Pick a book containing lots of four digit numbers (for example a telephone directory or book of maths tables) and choose a number, let's call it $N$, from the book, at random.

Since the knight is the only piece that moves asymmetrically in chess, more problems have been based on the knight than on any other chess piece.

In the middle of the page you can see a sharply pointed solid, formed by congruent "kite" shaped rectangles.

Q.479 If $a679b$ is a five-digit number (in base 10) which is divisible by 72, determine $a$ and $b$.

Q.455 The rule for leap years runs as follows: A year which is divisible by 4 is a leap year except that years which are divisible by 100 are not leap years unless they are divisible by 400.