Two men $\text{X}$ and $\text{Y}$ start from a place walking at $5.5 \; \text{km/h}$ and $6 \; \text{km/h}$ respectively. What is the time they will take to be $69 \; \text{km}$ apart, if they walk in opposite directions?

- $6$ hours
- $8$ hours
- $11.5$ hours
- $6$ hours $45$ minutes