A line moves up 4 units for every 6 units to the right. What is the slope?

• A. 2/3
• B. 3/2
• C. -2/3
• D. 0

Answer: (A)

Slope is the ratio of vertical change to horizontal change as you move along the line. Here, the line rises 4 units for every 6 units to the right, so rise = 4 and run = 6. The slope is 4/6, which simplifies to 2/3. A positive slope means the line goes up as you move to the right, so for each 1 unit to the right, the vertical change is 2/3 unit. If the line rose more or less for the same run, the slope would be accordingly larger or smaller (for example, a rise of 6 for a run of 4 gives a slope of 3/2; a zero rise gives a slope of 0). Therefore, the slope is 2/3.