n! is defined as n x (n - 1) x (n - 2) x ... x 2 x 1

5! = 120 shown

herePermutations are the number of ways you can choose r items from a total of n items (uniqueness

__not__ required)

_{12}P

_{5} = 95,040 shown

hereCombinations are the number of ways you can choose r

__unique__ items from a total of n items

_{n}C_{r} = | n! |

| r!(n - r)! |

_{12}C

_{5} = 792 shown

hereLogarithms are defined by the equation Log a

_{b} = e

Log 1000

_{b} = 3, we get b = 10 shown

hereLog(ab) = Log(a) + Log(b)

Log(x/y) = Log(x) - Log(y)