Question

Which graph shows the equation V = 4 + 2t, where V is the total volume of water in a bucket and t is the elapsed time in minutes?

On a coordinate plane, the x-axis shows elapsed time in minutes (t) and the y-axis shows total volume of water (V). A straight line with a positive slope begins at point (0, 3) and ends at point (5.5, 24).
On a coordinate plane, the x-axis shows elapsed time in minutes (t) and the y-axis shows total volume of water (V). Solid circles are at points (0, 3), (1, 6), (2, 10), (3, 14), (4, 18), (5, 22).
On a coordinate plane, the x-axis shows elapsed time in minutes (t) and the y-axis shows total volume of water (V). A straight line with a positive slope begins at point (0, 4) and ends at point (6, 16).
On a coordinate plane, the x-axis shows elapsed time in minutes (t) and the y-axis shows total volume of water (V). Solid circles are at points (0, 4), (1, 6), (2, 8), (3, 10), (4, 12), (5, 14), (6, 16).

Answer 1

Choose the graph that begins at (0, 4) and goes to (6, 16) (the third description).

Reason: V(0) = 4 (y-intercept 4) and slope = 2, so V increases by 2 each minute: V = 4, 6, 8, 10, 12, 14, 16. The straight line from (0,4) to (6,16) has slope (16−4)/6 = 2. (The fourth option lists the same points as discrete dots.)