Find the number of different meals of 4 items that you can get from the given menu of 6 items and no need to choose different items.

a) 120 b) 126 c) 5040 d) 15

• total item : 6
  we can select : 4
  
  thus -> 6C4 which = 6C2
  :: 6*5/ 2*1 = 15
• 9 years agoHelpfull: Yes(15) No(7)
• When order doesn't matter, and each object can be chosen more than once, the number of combinations is nCr = (n+r-1)!/[r!(n-1)!];where n is the number of total objects and r is the number chosen.
  There are 6 choices on this menu and 4 items should be ordered.
  Note that, duplicate items can be ordered (the 4 items don't have to be distinct).
  
  so Combinations with Repetition.
  
  nCr = (n+r-1)!/[r!(n-1)!]
  Here, n = 6 and r = 4.
  Therefore, required number of combinations = (6 + 4 - 1)!/4!(6 - 1)! = 9!/4!5! = 126.
  
  Hence, the answer is 126.
  
  
• 8 years agoHelpfull: Yes(10) No(2)
• d)15
  6C4 out of 6 we have to select 4
• 9 years agoHelpfull: Yes(6) No(3)
• d)15
  select new group from existing one so combination is used.6C4
• 9 years agoHelpfull: Yes(2) No(2)
• There are 6 choices on this menu and 4 items should be ordered.
  Note that, duplicate items can be ordered (the 4 items don't have to be distinct).
  
  For this kind of problems with large numbers, we can directly use the formula 3 (Combinations with Repetition) mentioned above;
  
  nPr = (n+r-1)!/[r!(n-1)!];where n is the number of total objects and r is the number chosen.
  
  Here, n = 6 and r = 4.
  Therefore, required number of combinations = (6 + 4 - 1)!/4!(6 - 1)! = 9!/4!5! = 126.
  
  Hence, the answer is 126.
• 7 years agoHelpfull: Yes(2) No(3)
• 15 is right
• 9 years agoHelpfull: Yes(1) No(3)
• 6C4 is the right answer.
• 9 years agoHelpfull: Yes(1) No(1)
• 6C4= 6!/2! 4!= 30/2=15
• 9 years agoHelpfull: Yes(1) No(3)
• 6C4(4 different items from 6 item)
  d.15
  
• 9 years agoHelpfull: Yes(1) No(2)
• nPr=(n+r-1)!/((n)!*(n-1)!)
  use it and solve the question. answer will be 126.
• 8 years agoHelpfull: Yes(1) No(0)
• 120 becz of 6 meals
• 9 years agoHelpfull: Yes(0) No(5)