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)
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?