Volume 11

1975 In Vol. 11 No. 1, W.J. Ryan asked several questions about Pythagorean triples, which I will try to answer.

A chain is as strong as its weakest link, and this applies particularly to the chain of mathematical argument.

One of the interesting applications of arithmetic series is the result that
$$\sum_{r=1}^n r = 1+2+3+\ldots + n = \frac{1}{2} n (n+1)$$

Recently I found the following relationship between $n!$ and $n^n$ while working through sequences and series:

Mastermind is a game which goes by several different names, and you make already know it, perhaps as "bulls and hits".

Question 1: In fact, the two numbers must each end in zero (see solution in last issue of Parabola)

"Mathematical Puzzles and Perplexities" by Claude Birthwhistle

Q.285 C.F. Gauss was given the problem of summing the numbers from 1 to 100 when he was a student. He did it this way:

Q.273 What is the smallest and largest possilbe number of Fridays that can occur on the 13th of a month in any calendar year?