実行時間を計測するメソッド

def time_check(loop = 1)
	start_time = Time.now
	loop.times do
	yield
	end
	end_time = Time.now
	end_time - start_time
end

使い方

triples = "AAA".."ZZZ"

time_include = time_check(10**6) { triples.include? "ABC" }
puts time_include