If anyone can please check what I have done, that would be awesome,
62. Class rings: You want to purchase a class ring. The ring can be made from three different metals, six different designs, and twelve stones. How many different class rings are possible? 216 class rings are possible.
I used the fundamental counting principal. 12*3*6=216 different rings. Mr F says: Correct.
64. Photography: A photographer lines up 15 members of a family in a single line in order to take a single photograph. How many different ways can the photographer arrange the family for the picture?
The photographer can arrange the family in 225 different ways because he wants them in a single line for a single photograph. There are 15 family members, and 15^2= 225 different ways. Mr F says: Incorrect. It's 15! ways.
66. Music: The window of a music store has eight stands in a fixed position where instruments can be displayed. In how many ways can three identical guitars, two identical keyboards, and three identical violins be displayed?
I used the fundamental counting principal, and got 18. 3*2*3=18 But I know that's not right because the instruments are identical, it's not like they're different. Is the answer 3? Mr F says: No. The answer is .
Thank you very much