What are the odds or randomly selecting the burned match from a bundle of matches?

matches.rb

Match = Struct.new(:burned)

PEOPLE = 4
TRIALS = 1_000_000

matches = Array.new(PEOPLE-1).fill(Match.new(false)).push(Match.new(true))
results = Array.new(PEOPLE).fill(0)

TRIALS.times do
  matches.shuffle!

  matches.each_with_index do |match, index|
    if match.burned
      results[index] += 1
    end
  end
end

results.each_with_index do |r, i|
  percent = (r.to_f / TRIALS * 100).round(2)
  puts "Person #{i+1} got the burned match #{r} (#{percent}%) times."
end

# => Person 1 got the burned match 249419 (24.94%) times.
# => Person 2 got the burned match 250346 (25.03%) times.
# => Person 3 got the burned match 250348 (25.03%) times.
# => Person 4 got the burned match 249887 (24.99%) times.

We assume that shuffling the array each time is a adequate representation of the first person randomly selecting the first item, then the second person randomly selecting the second item.

Then when everyone has selected their match, we record which person got the burned match, and repeat.

cc: @jayme-mckiney @supertopher @darrenboyd