If it would take 6 cows 3 days, or 3 cows 7 days to eat a field of grass, how many days would it take 1 cow to do it?Tags: MathsChallenge
The following was part of my 14 year old son’s homework.
Given a positive integer, form all unique permutations of that number, add them all up then divide by the sum of the digits (in the original number). What is the result?
Bear in mind that some of the digits may occur more than once.
e.g. Starting with [...]
Find a simplified expression for:
1/2! + 2/3! + 3/4! + … + n/(n+1)!