How to convert 390 US customary cups to imperial gallons?
We know (by definition) that:
We can set up a proportion to solve for the number of imperial gallons.
Now, we cross multiply to solve for our unknown :
Conversion in the opposite direction
The inverse of the conversion factor is that 1 imperial gallon is equal to 0.0492697405335325 times 390 US customary cups.
It can also be expressed as: 390 US customary cups is equal to imperial gallons.
An approximate numerical result would be: three hundred and ninety US customary cups is about twenty point three zero imperial gallons, or alternatively, a imperial gallon is about zero point zero five times three hundred and ninety US customary cups.
 The precision is 15 significant digits (fourteen digits to the right of the decimal point).Results may contain small errors due to the use of floating point arithmetic.