Enter a problem...
Finite Math Examples
P45
Step 1
Evaluate P45 using the formula Prn=n!(n-r)!.
5!(5-4)!
Step 2
Subtract 4 from 5.
5!(1)!
Step 3
Step 3.1
Simplify the numerator.
Step 3.1.1
Expand 5! to 5⋅4⋅3⋅2⋅1.
5⋅4⋅3⋅2⋅1(1)!
Step 3.1.2
Multiply 5⋅4⋅3⋅2⋅1.
Step 3.1.2.1
Multiply 5 by 4.
20⋅3⋅2⋅1(1)!
Step 3.1.2.2
Multiply 20 by 3.
60⋅2⋅1(1)!
Step 3.1.2.3
Multiply 60 by 2.
120⋅1(1)!
Step 3.1.2.4
Multiply 120 by 1.
120(1)!
120(1)!
120(1)!
Step 3.2
Expand (1)! to 1.
1201
Step 3.3
Divide 120 by 1.
120
120