Step 1: Simplify Quantity B
Quantity $\(B=\frac{1}{5}-\frac{1}{10}=\frac{2}{10}-\frac{1}{10}=\frac{1}{10}\)$
Step 2: Analyze Quantity A
Since $\(a<b\)$ and $\(a, b>5\)$ :
1. $\(\frac{1}{a}>\frac{1}{b}\)$ (because $a<b$ for positives).
2. The difference $\(\frac{1}{a}-\frac{1}{b}\)$ is positive but how large is it?

Step 3: Find Extremes for Quantity A
- Maximum possible value:

Occurs when $a$ is minimized and $b$ is maximized.
Let $\(a \rightarrow 5^{+}\)$and $\(b \rightarrow 10^{-}\)$:

$$
\(\frac{1}{5}-\frac{1}{10}=\frac{1}{10}\)
$$

- Minimum possible value:

Occurs when $a$ and $b$ are closest (e.g., $a=6, b=7$ ):

$$
\(\frac{1}{6}-\frac{1}{7}=\frac{1}{42}\)
$$


Step 4: Compare Quantities
- Quantity A ranges from $\(\frac{1}{42}\)$ to $\(\frac{1}{10}\)$.
- Quantity B is exactly $\(\frac{1}{10}\)$.