Permutation
Evaluate the expression
19 P 2
4 P r if there is no r would the answer be
just 4 or 0
19 P 2
= 19!/(19-2)!
= 19(18)(17!)/(17!
= 19(18)
= 342
If by "if there is no r" you mean "if the value of r = 0"
then
4P0
= 4!/(4-0)!
= 1
thank you
Permutation is a mathematical concept that deals with the arrangement of elements in a specific order. It is denoted by the notation "nPk" or "nPr", where "n" represents the total number of elements and "k" or "r" represents the number of elements taken at a time.
To evaluate the expression 19 P 2, we need to use the formula for permutation:
nPk = n! / (n - k)!
Here, "!" denotes the factorial of a number, which means multiplying the number by all positive whole numbers less than it.
So, let's calculate 19 P 2:
19! / (19 - 2)!
= 19! / 17!
= (19 * 18 * 17!) / 17!
= 19 * 18
= 342
Therefore, the value of 19 P 2 is 342.
Now, let's consider the expression 4 P r. If there is no value given for "r", we cannot determine the specific number of elements to be taken at a time. In permutations, the value of "r" is crucial, and without it, we cannot evaluate the expression.
Hence, if there is no value for "r", we cannot calculate 4 P r, and the answer would be indeterminate or undefined in this case.