Condation_if_else.rb

 num =110

 if num <50
   puts "fail"
 elsif num >=50  && num <=60
   puts "E"
 elsif num >60  && num <=70
   puts "D"
 elsif num >70  && num <=80
   puts "C"
 elsif num >80  && num <=90
   puts "B"
 elsif num >90  && num <=100
   puts "A"
 else
   puts "out of range"
 end
 puts "progam done"