Practice questions on if and else

puts "Enter length"
length = gets.chomp.to_i
puts "Enter breadth"
breadth = gets.chomp.to_i
if length == breadth
  puts "Yes, it is square"
else
  puts "No, it is only Rectangle"
end

puts "Enter first number"
first = gets.chomp.to_i
puts "Enter second number"
second = gets.chomp.to_i
if first>second
  puts "Greatest is",first
elsif second>first
  puts "Greatest is",second
else
  puts "Both are equal"
end

puts "Enter quantity"
quantity = gets.chomp.to_i
if quantity*100 > 1000
  puts "Cost is #{((quantity*100)-(0.1*quantity*100))}"
else
  puts "Cost is",quantity*100
end

puts "Enter salary"
salary = gets.chomp.to_i
puts "Enter year of service"
yos = gets.chomp.to_i
if yos>5
  puts "Bonus is #{0.05*salary}"
else
  puts "No bonus"
end

puts "Enter marks"
marks = gets.chomp.to_i
if marks<25
  puts "F"
elsif marks>=25 and marks<45
  puts "E"
elsif marks>=45 and marks<50
  puts "D"
elsif marks>=50 and marks<60
  puts "C"
elsif marks>=60 and marks<80
  puts "B"
else
  puts "A"
end

puts "Enter first age"
first = gets.chomp.to_i
puts "Enter second age"
second = gets.chomp.to_i
puts "third age"
third = gets.chomp.to_i

if first >= second && first >= third
  puts "Oldest is #{first}"
elsif second >= first && second >= third
  puts "Oldest is #{second}"
elsif third >= first && third >= second
  puts "Oldest is #{third}"
else
  puts "All are equal"
end

#find youngest yourself
#After this also check if two are equal, then which two				

puts "Enter a number"
number = gets.chomp.to_i
if number<0
  puts number*-1
else
  puts number
end

puts "Number of classes held"
noh = gets.chomp.to_i
puts "Number of classes attended"
noa = gets.chomp.to_i
atten = (noa/noh.to_f)*100
puts "Attendence is #{atten}"
if atten >= 75
  puts "You are allowed to sit in exam"
else
  puts "Sorry, you are not allowed. Attend more classes from next time."
end