A bank assigns random 4-digit numbers for ATM access codes. In each code, no digit is repeated.
How many arrangements of 4 digits can be chosen from 10 digits, if order is not important?

step-by-step explanation:

12475909

c.

step-by-step explanation:

she should of added 9^2 and 12^2. that is because it is a^2+b^2=c^2. c^2 is the hypotenuse and should always be bigger than the other two numbers. which is why she should of added 9 squared and 12 squared together instead of 15 squared.

it would open into a square depending on the type of envelope i’m not sure about the second part