In how many different ways can the top two positions be filled in a table tennis competition of 7 teams?
How many 3-digit numbers can be formed using the digits 2, 3, 4, 5, and 6:
a) as often as desired? b) once only?
The Attempt at a Solution
I can find the solution using the long way, but I'm wondering if there is a more logical and mathematical way to approach these equations?