ON 5
(Use commas to separate thousands, e.g. 25000000 should 25,000,000)
Permutations: When the order of selection matters, 7 items can be selected from a pool of 20 items in 390700900 ways.
When the order of selection does not matter, 7 items can be selected from a pool of 20 items in 77520 ways.Combinations: