Whats the answer? How do I understand it?

Quick translate "x is 12 units from 20" into an equation. what are the values of x being described? if you can answer any of my other questions that'd be great too

Arestaurant gives out a scratch-off card to every customer. the probability that a customer will win a prize from a scratch-off card is 25%. design and conduct a simulation using random numbers to find the experimental probability that a customer will need more than 3 cards in order to win a prize. justify the model for your simulation, and conduct at least 10 trials.

Gregory draws a scale drawing of his room. the scale that he uses is 1 cm : 4 ft. on his drawing, the room is 3 centimeters long. which equation can be used to find the actual length of gregory's room?