How many integers between 1500 and 8000 (inclusive) contain no repeated digits?

int.rb

#!/usr/bin/env ruby
# Author: Shawn Smith
# Purpose: Do nins math work
# Problem: How many integers between 1500 and 8000 (inclusive) contain no repeated digits?

total = 0

for x in 1500..8000 do
	number = x.to_s

	number_array = number.split('')

	if number_array.uniq.length == number_array.length
		total += 1
	end

	puts total
end