use the ! logical negation operator


temperature = 76
if !(temperature < 65 || temperature > 85)
  puts "Picnic time!"
else
  puts "Sorry, no picnic today."
end

1.	Conditional Statements
2.	Use the if Statement
3.	The simple form of an if statement looks like this
4.	An if statement with an else clause looks like in general (the else clause is optional)
5.	Syntax of using elsif Clauses in if Statements
6.	if statement contains several elsif statements
7.	write elsif statement a little tighter by using colons after the symbols:
8.	The if Statement with constant
9.	Use an elsif Clause
10.	if and unless also supply the else condition
11.	Using else Clauses in if Statements
12.	use the multiline if/else option
13.	put any number of lines of code in between the if statement and the end line:
14.	nest if logic
15.	we dropped then from the if statement.
16.	lay out an if statement is by replacing the then with a colon (:)
17.	Use if statement to check the user input

use the ! logical negation operator : If « Statement « Ruby