18 1/2 : 10

To calculate the ratio \( 18 \frac{1}{2} : 10 \), first convert \( 18 \frac{1}{2} \) to an improper fraction or decimal.

1. Convert \( 18 \frac{1}{2} \) to decimal: \[ 18 \frac{1}{2} = 18 + 0.5 = 18.5 \]

2. Now, you can express the ratio: \[ 18.5 : 10 \]

3. To simplify this ratio, divide both parts by 10: \[ \frac{18.5}{10} : \frac{10}{10} = 1.85 : 1 \]

Thus, the simplified ratio is \( 1.85 : 1 \) or \( 18.5 : 10 \) in its original form.