gistfile1.rb

#!/usr/bin/ruby

# This program adds up the numbers 1 through 10,000 using 100 threads.

# Challenge A: Does this solution have any problems? If so, explain.
# Challenge B: Propose an alternate implementation that does not use threads.

n = 10000

p (1..n).reduce(:+) # by iteration
p (n / 2) * (n + 1) # by math