Answer:
b
Step-by-step explanation:
make a formula, its the easiest way to solve problems like these also its very efficent
If all 25 questions are different,
When order of selection counts:
P(25,7)
=25!/(25-7)!
=15511210043330985984000000/6402373705728000
=2422728000
When order of selection does not count count:
C(25,7)
=25!/(7!*(25-7)!)
=15511210043330985984000000/(6402373705728000*5040)
=480700
Ｆ（５） ＝ －２ ＊ ５ ＋ １ ＝ －９
ｔｈｅ ｐａｉｒ ｉｓ （５， －９）
