How many numbers can be formed using parenthesis in the expression 7/8/9/10/11??

• 2^3=8
  because try it with onle 3 no. result would be 2
  and try it with 4 numbers result would be 4
  so for 5 number it should be 8
  i.e 2^n-2
  
• 9 years agoHelpfull: Yes(2) No(3)
• can any one explain it in detail
• 8 years agoHelpfull: Yes(0) No(0)