Find the ratio of :
520 ml to `6.5` litres.

Answer

To find the ratio of 520 ml to 6.5 liters, we will follow these steps:

### Step 1: Convert liters to milliliters
Since the two quantities need to be in the same unit for comparison, we will convert 6.5 liters to milliliters. We know that:
1 liter = 1000 milliliters.

So, we can calculate:
\[ 6.5 \text{ liters} = 6.5 \times 1000 \text{ ml} = 6500 \text{ ml} \]

### Step 2: Write the ratio
Now that both quantities are in milliliters, we can write the ratio of 520 ml to 6500 ml:
\[ \text{Ratio} = \frac{520 \text{ ml}}{6500 \text{ ml}} \]

### Step 3: Simplify the ratio
We can simplify the ratio by canceling out the "ml" units:
\[ \text{Ratio} = \frac{520}{6500} \]

Next, we will simplify the fraction. We can divide both the numerator and the denominator by 520:
\[ \frac{520 \div 520}{6500 \div 520} = \frac{1}{12.5} \]

To express this as a ratio of whole numbers, we can multiply both the numerator and the denominator by 2 to eliminate the decimal:
\[ \frac{1 \times 2}{12.5 \times 2} = \frac{2}{25} \]

### Final Answer
Thus, the ratio of 520 ml to 6.5 liters is:
\[ \text{Ratio} = 2 : 25 \]

---