Question

How many different ways can the front row seats be filled with 20 students if the classroom has 4 rows of seat?

Answer 1

use combination
\[nCr = \frac{n!}{r!(n-r)!}\]
\[20C4 = \frac{20!}{4!(20-4)!}\]

Answer 2

do you get it?

Answer 3

So it would be 4,845?

Answer 4

let me get my scientific calculator

Answer 5

yup.you're right

Answer 6

Ok, Thanks!

Answer 7

<tips imaginary hat>

Answer 8

haha :)