Question

How many different ways can the front row seats be filled with 20 students if the classroom has 4 rows of seats? 1,860,480 116,280 4,845?

Answer 1

1860480 ways the front row seats can be filled

Answer 2

we know that

The formula for combinations is

`C=n!/((n-r)!*r!)`

where

n is the total number of objects you choose from

r is the number that you choose to arrange

in this problem

`n=20\\ r=4`

`C=20!/[(20-4)!*4!]\\ C=20!/[(16)!*4!]\\ C=4,845`

therefore

the answer is

`4,845`