Look on the back of any modern book and you will find an ISBN code. Take this code and calculate this sum in the way shown. Can you see what the answers always have in common?
Weekly Problem 25 - 2006
When coins are put into piles of six 3 remain and in piles of eight 7 remain. How many remain when they are put into piles of 24?
In a square in which the houses are evenly spaced around the
outside, numbers $3$ and $10$ are opposite each other.
What is the smallest number of houses in the square?
What is the largest possible number of houses in the square?