1. The table shows the relationship between y, the cost to rent a bicycle, and x, the amount of time the bicycle is rented in hours. Bicycle Rental Costs
Time, x
(hours) Total cost, y
(dollars)
1 $10
2 $20
3 $30

Part 1: A student drew the following graph to represent this situation. Explain the error in the graph. (Answer box on following page.)

Set $r$ is a set of rectangles such that (1) only the grid points shown here are used as vertices, (2) all sides are vertical or horizontal and (3) no two rectangles in the set are congruent. if $r$ contains the maximum possible number of rectangles given these conditions, what fraction of the rectangles in set $r$ are squares? express your answer as a common fraction.