How do you evaluate 100P5 using a calculator?

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Answer 1 · 2017-06-27T12:05:28

It all depends on what calculator you have got.

$^{100} P_{5} = 9034502400$ $color(white)()^(100)P_5=9034502400$

Assumption: This is meant to be permutation $\to^{100} P_{5}$ $->color(white)()^(100)P_5$

Using: $\frac{n!}{(n - r)!}$ $" "(n!)/((n-r)!)$

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

$=9034502400$
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$color(blue)("Foot note")$

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 $color(white)()^nC_r ->(n!)/((n-r)!r!)$