Question

Amir wants to create a 4-digit password for his phone. He wants to choose 4 different numbers between 1 and 5 inclusive. Calculate the total number of 4-digit passwords that Amir can create.​

Answer 1

The right answer is 120. Let abcd represent the numbers. The number have to be different meaning no repeats so that would mean:
a has 5 choices of numbers
b had 4
c has 3
d has 2
So the equation would be 5x4x3x2 = 120

Answer 2

• 625

Explanation:

Let the digits be:

• abcd

Each of them include numbers 1 through 5.

For each digit there are 5 options.

Total number of combinations is:

• 5*5*5*5 = 625