Mr. Alexander
This page lists questions and answers that were posted by visitors named Mr. Alexander.
Questions
The following questions were asked by visitors named Mr. Alexander.
We call a number special if every digit in the number either is a 1 or borders a 1. For example, 11111, 13, 141, 1441, 515151, and 101 are all special, but 10001, 222, 122, and 1333 are not special. How many 2-digit numbers are special?
10 years ago
In how many ways can 4 boys and 4 girls sit around a circle table if each boy sits directly between two girls? (Rotations of the same arrangement are still considered the same. Each boy and girl is unique, not interchangeable.)
9 years ago
How many 2-letter "words" consist of two different letters arranged in alphabetical order? (Any two letters together is considered a "word." For example, one such word is dq.)
9 years ago
Answers
The following answers were posted by visitors named Mr. Alexander.