What is 3!/5! written in standard form?

We can write out 3! (three factorial) as 3x2x1, and we can write out 5! as 5x4x3x2x1.
This means that, since 3x2x1 is on the top and the bottom of the fraction, it cancels out.
This leaves us with 1 on top, and 4x5=20 on the bottom.
This means the answer is 1/20, which is 0.05.
Written is standard form, this is 5x10^-2