To find out how many times larger the volume of the saltwater tank is compared to the volume of the freshwater tank, we first need to calculate the volumes of both tanks.
The volume \( V \) of a cube can be calculated using the formula:
\[ V = \text{side length}^3 \]
1. Volume of the freshwater tank: The side length of the freshwater tank is 15 cm.
\[ V_{\text{freshwater}} = 15^3 = 15 \times 15 \times 15 = 3375 \text{ cm}^3 \]
2. Volume of the saltwater tank: The side length of the saltwater tank is 75 cm.
\[ V_{\text{saltwater}} = 75^3 = 75 \times 75 \times 75 = 421875 \text{ cm}^3 \]
3. Now, we find out how many times larger the volume of the saltwater tank is than the volume of the freshwater tank:
\[ \text{Ratio} = \frac{V_{\text{saltwater}}}{V_{\text{freshwater}}} = \frac{421875}{3375} \]
Now, to simplify it, we can divide:
\[ \frac{421875 \div 3375} = 125 \]
To answer the question: "How many times larger is the volume of the saltwater tank than the volume of the freshwater tank?", the final answer is:
\[ \text{The volume of the saltwater tank is } 125 \text{ times larger than the volume of the freshwater tank.} \]
However, it appears there might be a discrepancy in the options provided since none of them include 125. Could you please check the question or the choices again?