SOLUTION: Suppose that a class of 30 students is assigned to write essay. 1) Suppose 4 essays are randomly chosen to appear on the class bulletin board. How many different groups of 4 are po

Algebra ->  Probability-and-statistics -> SOLUTION: Suppose that a class of 30 students is assigned to write essay. 1) Suppose 4 essays are randomly chosen to appear on the class bulletin board. How many different groups of 4 are po      Log On


   



Question 228739: Suppose that a class of 30 students is assigned to write essay. 1) Suppose 4 essays are randomly chosen to appear on the class bulletin board. How many different groups of 4 are possible? I said 4/30*3/29*2/28*1/27= 24/657720=3/82,215 I think.
2) Suppose 4 essays are randomly chosen for awards of $10,$7,$5 and $3. How many different groups of 4 are possible? 24

Answer by user_dude2008(1862) About Me  (Show Source):
You can put this solution on YOUR website!
1) 30 C 4 = (30!)/(4!(30-4)!) = 30!/(4!26!) = (30*29*28*27)/(4*3*2*1) = 27,405
Answer: 27,405 different groups

2) 4 P 4 = 4!/(4-4)! = 4!/0! = 4!/1 = 4! = 4*3*2*1 = 24
Answer: 24 different groups