Respuesta :

1/4 of the list price was off, so $90 was 3/4 of the list price. (1 -1/4= 3/4).

We have an equation: 90/? = (3/4)/1

Cross multiply:
3/4*? = 90*1
⇒ ?= 90*1/(3/4)= 90*1* (4/3)= 120.

The list price was $120.

Hope this helps~