Question 59864
I do not understand how to tell when to use combination and when to use permutation. 
You use permutations when order is important, like how many ways to have a phone number, social security number or liscence plate number, committee members who are president, vice pres, treas., or secr..
You use combinations when order is not important like lottery numbers, committee members (all of equal standing), cards.
The word problem is: Jack has seven frozen meals in his freezer. How many ways can he choose to have them for dinner Sunday through Saturday?
You don't need either for this problem, but you can use permutations because you are concerned with the order of the meals.
There are 7 chices the first day, 6 the second, 5 the third, 4 the fourth, 3 the fifth, 2 the sixth, and 1 the last.
7*6*5*4*3*2*1=7!= 5040 <---counting method (if I remember the terminology correctly)
7 nPr 7=5040 <---permutation
Happy Calculating!!!