# What factorial equals 720?

Jun 23, 2015

Let's first do it the hard way.

#### Explanation:

You're trying to find out the solution for
n! =720
This means $1 \cdot 2 \cdot 3 \cdot \ldots \cdot n = 720$

You can divide by all consequtive numbers untill you end up with $1$ as a result:
$720 / 1 = 720 , 720 / 2 = 360 , 360 / 3 = 120$ etc.

GC (TI-83):
MATH - PRB - !
And try a few numbers.