The school student council sponsored a switch day where students were able to switch classes every 20 minutes. the students are in school for 7 hours. if a student switched as often as possible, how many classrooms in all did that student visit? (hint there are 60 minutes in 1 hour)

Lin is writing an equation to model the proportional relationship between y, the total cost in dollars of downloading videos from a website, and x, the number of videos downloaded. she knows that the total cost to download 3 videos was $12. her work to find the equation is shown below. joylin’s work step 1 k= 3/12= 0.25 step 2 y= 0.25x where did joylin make her first error?