No chart has been provided, so I've created a table with some x and y values. y=½x represents the number of pages read (y) in a give time (x) at a reading rate of half a page a minute (or one page in two minutes).
| y pages |
x minutes |
| 0 |
0 (start) |
| ½ |
1 |
| 1 |
2 |
| 1½ |
3 |
| 2 |
4 |
| 2½ |
5 |
| 3 |
6 |
| 3½ |
7 |
| 4 |
8 |
| 4½ |
9 |
The chart can be represented by a straight line graph. (0,0), the origin, represents where reading started. Plot any (x,y) value. For example, (8,4). Draw a line from the origin through (8,4). All points on the line will match the table and for any number of minutes you can see how many pages are read.