You have to write a function printer_error which given a string will output the error rate of the printer as a string representing a rational whose numerator is the number of errors and the denominator the length of the control string. Don't reduce this fraction to a simpler expression.

printer_errors.rb

def printer_error(s)
	"#{s.count('n-z')}/#{s.size}"
end

##### Before refactor #####

def printer_error(s)
  error_num = s.split('').count {|s| s =~ /[n-z]/}
  "#{error_num}/#{s.size}"
end