Which models selecting a combination of 3 objects taken from a group of 8 items?

  see attached

Step-by-step explanation:

nCk models k objects taken from a group of n.

  nCk = n!/(k!·(n-k)!)

Fill in n=8 and k=3 to get ...

  8C3 = 8!/(3!·5!)

to find the unit price, we must figure out the cost of one item (in this case one dish towel).   to do this, we divide the total price ($7.92) by the number of items bought (for this problem it is 8, because there are eight dish towels in one pack).  

$7.92/8 = $0.99

therefore, the unit price, or the price of one dish towel, is $0.99.

hope this !