Is this a valid use example?

Question

"El descuento está a 20% (ahora)". Is this a correct way to use this kind of costruct?Thank you as always!

Accepted Answer

Hola Gabor
You could say in a very colloquial way, for example:
El descuento está al 20%.
This would indicate in a similar way as in using estar a with fluctuating quantities and prices, that there is a discount "now" which is a 20%. This is the same as saying "Hay un descuento ahora del 20%" or "El descuento ahora es el 20%".
Saludos

Answer

Thank you! If anyone else is reading this (and for my notes), it seems that percentages always require "el", which turns my "a" into an "al".