How do you evaluate 100P5 using a calculator?

Question

2417 views around the world

You can reuse this answer
Creative Commons License

Answer 1 · 2017-06-27T12:05:28

It all depends on what calculator you have got.

#color(white)()^(100)P_5=9034502400#

Assumption: This is meant to be permutation #->color(white)()^(100)P_5#

Using:#" "(n!)/((n-r)!)#

#(100xx99xx98xx97xx96xxcancel(95!))/(cancel(95!))#

#=9034502400#
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
#color(blue)("Foot note")#

Permutation is a higher count than that for combinations.

Permutation #-># the order matters: ab is not the same as ba.

Combination #-># the order does not matter: ab is considered the same as ba

The expression for combinations is # color(white)()^nC_r ->(n!)/((n-r)!r!)#