You want to set up an aquarium and need to determine what size tank to buy. The graph shows tank sizes using a rule that relates the capacity of the tank to the combined lengths of the fish it can hold.
If you want four 2 in. platys, seven 1 in. guppies, and a 3 in. loach, what is the smallest capacity tank you can buy?
graph
Since we want to determine the smallest capacity tank that can accommodate four 2 in. platys, seven 1 in. guppies, and a 3 in. loach, we need to find the point on the graph where these three lengths coincide. Let's find the corresponding points on the graph for each of these lengths:
- Four 2 in. platys would require a length of 4 * 2 = 8 in.
- Seven 1 in. guppies would require a length of 7 * 1 = 7 in.
- One 3 in. loach would require a length of 3 in.
So, our combined length needed is 8 in. + 7 in. + 3 in. = 18 in.
From the graph, we can see that the smallest capacity tank that can accommodate a combined length of 18 in. is a tank with a capacity of 15 gallons.
Therefore, the smallest capacity tank you can buy is a 15-gallon tank.