Answer:
32,432,400
Step-by-step explanation:
This you can use a permutation.
P(15,7)15x14x13x12x11x10x9
There are 32,432,400 ways to arrange it.
Your answer of 10 x 12 - 14 +2+15 =123
Hope this helps you
I think is B
I added 12 on the ride