Question

Plz, help me with this question!

Answer 1

870

Explanation:

Assuming you mean

30
`P_(2)`

Using the definition

n
`P_(r)` =
`(n!)/((n-r)!)`

where n! = n(n - 1)(n - 2) ..... 3 × 2 × 1

Then

30
`P_(2)` =
`(30!)/(28!)` =
`(30(29)(28)(27)...)/(28(27)(26).....)`

Cancel the terms 28(27)... on numerator/ denominator, leaving

30
`P_(2)` = 30 × 29 = 870