This is the answer key, not my work. for question 7, how do you get the -3 and 2 to multiply the equations by

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.

This is about circle theorems. someone asap : (

The perimeter of a rectangle is 42 inches. if the width of the rectangle is 6 inches, what is the length