The graph shows the relationship between the cost of making cardboard boxes and the number of boxes made , what rate does the point (35,7) represent ? y=$ and x=boxes
7$/35boxes
7$/1$
35$/7boxes
35$/1box
i'm confused between 1 and 3 for the answers !

Astudent must have an average on five test that is greater than it equal to 80% but less than 90% to receive a final grade of b. devon's greades on the first four test were 78% 62% 91% and 80% what range if grades on the fifth test would give him a b in the course? ( assuming the highest grade is 100%)