I believe it’s the last one, but I could be wrong.. The n three times= 3n+15 (less than itself)-n ??
The first digit of the password can be any of the ten digits - 10 possibilities.
A digit cannot be repeated, so the second digit can be any digit except the one you chose for the first digit - 9 possibilities.
The third digit can be any digit except the digits you chose for the first and second digit - 8 possibilities.
Using the rule of product:

There are 720 passwords.
Answer:
(a) -6
Step-by-step explanation:
P(x) = ax^3 +bx - 3
- P(-1) = -a-b-3 = 0
- therefore a+b=-3
- P(1) = a+b-3
- P(1) = -3 - 3 = -6
- (a)
The answer is 1561 yuans and 27 jiao.
Answer:
375 + 320
Step-by-step explanation:
375 adult
320 students
equals 395