Question

16!/4!12! =



.0238
1,820
2,380

Answer 1

From Mathematica:\[\frac{16!}{4!*12!}=1820 \]

Answer 2

16!/(4!12!)
If you're dividing by 12!, then you can imagine a bunch of the numbers in 16! getting canceled out. Instead of 16 * 15 * 14 * 13 * 12 * ... * 2 * 1, we just have 16 * 15 * 14 * 13.

(16 * 15 * 14 * 13)/(4 * 3 * 2 * 1)
Canceling out what's in common...
(4 * 5 * 7 * 13)
20 * 7 * 13
260 * 7
1400 + 420
1820