Fibonacci sequence in Ruby

fibo.rb

require 'benchmark'

def fibo(n)
  x,y = 0,1
  n.times do
    x,y = y,x+y
  end
end

number = 100_000
printf "\nNumbers of the sequence: #{number}\n"

# warmup
fibo(number)
fibo(number)

puts Benchmark.measure { fibo(number) }