Current flow 5amps in a 120v circuit . what would the resistance be?

The current flowing through a circuit is equal to voltage divided by resistance:

I = U / R, and therefore R = U / I.

With your given data, R will be 24 Ohms.

It is helpful to remember following figure:

U

I R

If you ever want to calculate one of those values, cover it with your finger, and the rest will look like an equation. For example, when looking for I, cover I and the rest of figure gives you U over R.