To determine which graph accurately represents the scenario of the bathtub draining, we need to analyze the situation:
- The bathtub starts with 40 gallons of water.
- The water drains at a rate of 8 gallons per minute.
We can calculate how long it will take for the tub to empty completely. At a rate of 8 gallons per minute, it will take:
\[ \text{Time to empty} = \frac{40 \text{ gallons}}{8 \text{ gallons/minute}} = 5 \text{ minutes} \]
So, after 0 minutes, there are 40 gallons; after 1 minute, there will be 32 gallons; after 2 minutes, there will be 24 gallons; after 3 minutes, there will be 16 gallons; after 4 minutes, there will be 8 gallons; and after 5 minutes, there will be 0 gallons.
The relationship is linear, meaning the amount of water decreases at a constant rate. Therefore, the graph should be a straight line that starts at (0, 40) and ends at (5, 0).
Analyzing the options:
- First option: Straight line from (0, 40) to (5, 0). This is a correct representation.
- Second option: Concave upward curve from (0, 40) to (5, 0). This is incorrect since the water isn't draining gradually slower.
- Third option: Straight line from (0, 40) to (8, 0). This is also incorrect because it should end at (5, 0), not (8, 0).
- Fourth option: Concave downward curve from (0, 40) to (5, 0). This is incorrect since the water is draining at a constant rate.
Based on this analysis, the correct graph representing the relationship between the minutes and gallons of water in the tub is the first option.